A Study of the Existence of Rotation Isomerism in Tri-Alpha-Naphthylboron and Its Addition Compounds

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A Study of the Existence of Rotation Isomerism in Tri-Alpha-Naphthylboron and Its Addition Compounds

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PU R D U E UNIVERSITY

THIS IS TO CERTIFY THAT THE THESIS PREPARED UNDER MY SUPERVISION

by

Alex Z le tz

e n title d

_____________________________

A STUDY OF THE EXISTENCE OF ROTATION ISOMERISM IN

TRI-/JuHiA-NAPHTHYLBORON AND ITS ADDITION COMPOUNDS

COMPLIES WITH THE UNIVERSITY REGULATIONS ON GRADUATION THESES

AND IS APPROVED BY ME A S FULFILLING THIS PART OF THE REQUIREMENTS

FOR THE DEGREE OF

Ehe De

P r o f e s s o r i n C h a r g -e o r T h e s i s

H ead of S chool or D epartm ent

TO THE LIBRARIAN:----THIS THESIS IS NOT TO BE REGARDED A S CONFIDENTIAL.

PROFESS OH m

GRAJD. S C H O O L F O R M 9 —3 . 4 9 —IM

CHARGE

A STUDY OF THE EXISTENCE OF ROTATION ISOMERISM IN TRI-ALPHA-KAPHTHH^ORON AND ITS ADDITION COMPOUNDS A T h e sis S u b m itted t o t h e F a c u lty of Purdue U n iv e r s ity by A lex Z le tz I n P a r t i a l F u lf illm e n t o f th e R equirem ents f o r th e D egree of D o cto r o f P h ilo so p h y Ju n e, 1950

ProQuest Number: 27714159

All rights reserved INFORMATION TO ALL USERS The quality of this reproduction is d e p e n d e n t upon the quality of the copy subm itted. In the unlikely e v e n t that the a u thor did not send a c o m p le te m anuscript and there are missing pages, these will be noted. Also, if m aterial had to be rem oved, a n o te will ind ica te the deletion.

uest ProQuest 27714159 Published by ProQuest LLC (2019). C opyright of the Dissertation is held by the Author. All rights reserved. This work is protected against unauthorized copying under Title 17, United States C o d e M icroform Edition © ProQuest LLC. ProQuest LLC. 789 East Eisenhower Parkway P.O. Box 1346 Ann Arbor, Ml 48106 - 1346

Acknowl edgment I w ish t o acknow ledge iqy in d e b te d n e s s to P r o f e s s o r H e rb e rt C. Brown under whose g u id an ce t h i s r e s e a r c h has been c a r r i e d o u t. Many th a n k s a r e d u e t o him f o r encouragem ent and a d v ic e . I w ould a l s o l i k e t o e x p re ss ny a p p r e c ia tio n t o th e R e se a rc h C o rp o ra tio n and to th e Purdue R esearch F o u n d atio n f o r f i n a n c i a l a s s i s ta n c e w hich made t h i s stu d y p o s s i b l e .

TABLE OF CONTENTS Page ABSTRACT..................................................................................................................... CHAPTER I .

i

INTRODUCTION

S ta te m e n t of P r o b le m ......................

1

A L i t e r a t u r e S urvey o f t h e T r ia r y lb o ro n s and T h e ir A d d itio n Compounds

2

Comparison o f t h e O b s e rv a tio n s of Brown and S u j i s h i w ith ............................................ Those o f K rause and Nobbe

6

CHAPTER I I .

THE PREPARATION OF VARIOUS FORMS OF TRI-ALPHANAPHTHXLBORON AND ITS ADDITION COMPOUNDS

1 D i s c u s s i o n .......................................

11

The P r e p a r a tio n o f TNB by th e Method o f Brown .................................................. and S u j i s h i . . . . . . . .

11

The P r e p a r a tio n o f TNB by t h e Method of K rause and N o b b e ......................

12



P u r i f i c a t i o n o f TNB O b tain ed from t h e E th e r S o l u t i o n ..............................................................

13

The P r e p a r a tio n o f TNB-benzene fro m H e a t- tr e a te d TNB.

lh

E x p e rim e n ta l D e t a i l s ...........................................................................lU The P r e p a r a tio n o f TNB by t h e Method o f Brown and S u j i s h i • • • • • • . . . . . . . . . . . . . .

15

The P r e p a r a tio n of TNB by t h e M odified Method of Brown and S u j i s h i ...............................

16

The P r e p a r a tio n o f TNB by t h e P ro ced u re o f K rause and Nobbe .....................................................

19

The P r e p a r a tio n o f TNB b y a M odified P ro ced u re of K rause and Nobbe U sing a L a rg e r P r o p o rtio n o f E t h e r ..........................

20

The P u r i f i c a t i o n o f TNB U sing th e T h ree-b u lb A p p aratu s o f K rause and P o lack .................. . . . . . .

22

The P r e p a r a tio n o f T N B - b e n z e n e .......................................25

Page CHAPTER I I I .

THE BEHAVIOR OF TRI-ALPHA-NAPHTHYIBORON AND ITS ADDITION COMPOUNDS ÜTTHE SOLID STATE

O b se rv a tio n s and D i s c u s s i o n .................................................................... 26 D is s o c ia tio n P r e s s u r e M easurem ents o f TNB-ammonia. The O b se rv a tio n o f a Minimum i n th e P r e s s u r e c o m p o sitio n C u r v e ..................................................................

.

26

The B eh a v io r o f H e a t- tr e a te d TNB upon A d d itio n o f .......................... 50 Mole P e r Cent Ammonia

39

The B eh av io r o f TNB O btained fro m t h e K rause and Nobbe P ro c ed u re upon A d d itio n o f Ammonia . . . . .

1+0

An A ttem pt to P re p a re Sym m etrical TNB i n t h e S o lid S t a t e .................................................

U3

D is s o c ia tio n P r e s s u re M easurem ents on TNB-benzene . •

U5

The B eh a v io r o f TNB-benzene w ith A m m o n ia ............................51 The B eh av io r o f TNB, O b tain ed upon L ib e r a tio n of Benzene a t 8 0 °, w ith Ammonia ..................................... 52 E x p e rim en ta l D e t a i l s ................................ . . . . . . . . . . .

5U

P r e p a r a tio n and P u r i f i c a t i o n o f G a s e s ...............................

5U

D is s o c ia tio n P r e s s u re M easurem ents on TNB-ammonia . .

5U

An A ttem p t t o P re p a re S ym m etrical TN B ..........................

.

57

D is s o c ia tio n P r e s s u re M easurem ents on TNB-benzene • .

57

The B eh av io r o f TNB-benzene w ith A m m o n ia ......................

59

The B e h a v io r o f TNB, O b tain ed upon l i b e r a t i o n o f Benzene a t 8 0 °, w ith A m m o n ia ......................

65

CHAPTER IV .

THE NATURE OF THE PRODUCT OBTAINED BY RECRYSTAL­ LIZING HEAT-TREATED TRI-ALPHA-NAPHTHYLBORON FROM VARIOUS SOLVENTS AND THE' SOLUBILITY OF TRI-ALPHANAPHTHYLBORON

R e c r y s t a l l i z a t i o n o f H e a t- tr e a te d TNB from V ario u s S o l v e n t s ......................

69

Page I n t r o d u c t i o n .......................................................................................... 69 The Q u a l i t a t i v e R e s u lts o f P ro c e d u re No* 1

. . . . .

The R e s u lts o f P ro c e d u re No * 2 ........................................ D is c u s s io n

70 •

........................................

83

The B eh av io r o f t h e R e s id u a l TNB to w ard s 50 Mole ...................... P e r Cent Ammonia The S o l u b i l i t i e s o f TNB

72

85

. * * * * . . . * * * . . *

87

The S o l u b i l i t y o f TNB i n V ario u s S o lv e n ts from t h e D a ta o f P ro ced u re No*2

87

The S o l u b i l i t y o f D i f f e r e n t P r e p a r a tio n s o f TNB i n E t h e r ............................................. ................................... * * *

92

E x p e rim e n ta l D e t a i l s ....................................................................... ....

92

M a t e r i a l s ................................................................................................... 92 R e c r y s t a l l i z a t i o n o f H e a t- tr e a te d TNB from V arious S o lv e n ts . . . . . . . . P ro ced u re No. 1 P ro ced u re No. 2

. . . . . .

• • • • •

93

. . . . .

93

......................

93

The S o l u b i l i t y o f th e K rause and Nobbe TNB i n E th e r • CHAPTER V.

96

THE BEHAVIOR OF TRI-ALPHA-NAPHTHYLBORON AND ITS BENZENE SOLVATE IN SOLUTION

I n t r o d u c t i o n ........................................................................................................99 The R e a c tio n w ith

A m m o n ia ............................................................100

The R e a c tio n w ith

T r im e th y la m in e ...........

E x p e rim en ta l D e a t i l s

101

...............................

The R e a c tio n w ith A m m onia.......................

107 107

The R e a c tio n w ith T rim eth y l a m i n e .............................................I l l P re lim in a ry E xperim ents

.............................. I l l

P r e c i p i t a t i o n E xp erim en ts i n t h e Vacuum L in e

. • 116

Page CHAPTER V I.

THE EXISTENCE OF ROTATION ISOMERISM IN TRIALPHA-NAPHTHYLBORON AND ITS ADDITION COMPOUNDS

Summary o f R e s u lts P r e p a r a tio n s

.

..........................

• • • •

121*

..............................

• • • •

121*

B eh a v io r o f TNB and I t s A d d itio n Compounds i n t h e S o lid S t a t e .............................. 12l* The N atu re o f t h e P ro d u c t O b tain ed by Re c r y s t a l ­ l i z i n g H e a t- tr e a te d TNB from V ario u s S o lv e n ts and t h e S o l u b i l i t i e s o f TNB . . . . . . . . . . .

128

The B eh av io r of TNB and I t s Benzene S o lv a te i n S o lu tio n . . . . . . . • • • • •

129

D is c u s s io n . .

. . . .

. . . . . . . . . .

C o n c l u s i o n s .....................................................

. . . . . . .

131 135

BIBLIOGRAPHY..........................................................................................................136 VITA

LIST OF TABLES T ab le 1»

Page A L i s t o f T r ia r y lb o ro n s and T h e ir A d d itio n Compounds •with R e fe re n c e s to th e L i t e r a t u r e ................................................

3

2,

R a tio o f Benzene t o TUB i n T N B -b en zen e..................................

3*

D is s o c ia tio n P r e s s u r e s o f TNB-ammonia .

U.

Summary o f D is s o c ia tio n P r e s s u r e s f o r F iv e Samples o f . . . T N B -am m o n ia.....................................................

28

V a r ia tio n o f D is s o c ia tio n P r e s s u re o f TNB-ammonia m t h Change i n Mole P e r Cent o f Ammonia a t II4O0 . . . . . . . .

30

V a r ia tio n o f D is s o c ia tio n P r e s s u re o f TNB-anmonia w ith Change i n Mole P er Cent o f Anmonia a t lU 0° . . . . . . . .

35

V a r ia tio n o f D is s o c ia tio n P re s s u re o f TNB-ammonia w ith Change i n Mole P e r Cent o f Anmonia a t IÎ4O0 . . . . . . . .

36

5. 6. 7.

.

.......................

25 27

8.

Change o f P r e s s u r e w ith Time of F r e s h ly P re p a re d TNBammonia U sing H e a t- tr e a te d TNB a t 8 0 .0 Î 0 . 3 ° ............................ h i

9#

Change o f P r e s s u r e w ith Time of F r e s h ly P re p a re d TNBammonia U sing TNB from t h e K rause and Nobbe P r e p a r a tio n

.

hh

10.

D is s o c ia tio n P r e s s u re o f TNB-benzene, P r e p a r a tio n No. 1 , a t 2 5 . 0 ° .................................................................................................................h6

11.

D is s o c ia tio n P r e s s u re o f TNB-benzene, P r e p a r a tio n No. 1 , a t 3 9 . 1 ° .................................................................................................................h6

12*

D is s o c ia tio n P r e s s u r e o f TNB-benzene, P r e p a r a tio n No. 1 , w ith 97 Mole P e r Cent Benzene a t 25*0° ......................*

h7

D is s o c ia tio n P r e s s u re o f TNB-benzene, P r e p a ra tio n No. 2 , w ith 106 Mole P er C ent B e n z e n e ................................................ • • •

h7

D is s o c ia tio n P r e s s u re s o f TNB-benzene, P r e p a r a tio n No. 1 , w ith 97 Mole P e r Cent Benzene from t h e R everse R e a c tio n a t 2 5 . 0 ° ..............................

h9

D is s o c ia tio n P r e s s u re o f TNB-benzene, P r e p a r a tio n No. 2 , w ith 96 Mole P er Cent Benzene a t 2 5 . 0 ° ................................... .

h9

13* lh*

15*

Page

Table 16. 17• 18.

D is s o c ia tio n F re s s u re of TMB-benzene* P r e p a r a tio n No. 2 , Tüith 87 Mole P er Cent Benzene a t 2 £ > .0 ° .

50

D is s o c ia tio n P r e s s u re o f TNB-benzene, P r e p a r a tio n No. 2, ■with 7U Mole P e r Cent Benzene a t 2 5 * 0 ° ...........................

50

D is s o c ia tio n P re s s u re s o f TNB-ammonia O btained by R e a c tin g TNB-benzene and ammonia a t 30° and 8 0 ° .......................... 6 l

19 # V a r ia tio n o f P r e s s u re w ith Time of TNB-ammonia P re p a re d from TNB F re s h ly F re e d of Benzene a t 80° . T em perature =

80°

66

20*

D ata on T reatm ent o f TNB w ith V ario u s S o lv e n ts by P ro ced u re No* 1 .............................................................................................. 71

21.

Change o f Vapor P re s s u re w ith Change i n S o lv e n t Composi­ t i o n o f a S o lu tio n o f TNB i n Carbon T e tr a c h lo r id e a t 2 5 .0 ° . 73

22.

Change o f Vapor P r e s s u re w ith Change i n S o lv e n t Composi­ t i o n o f a S o lu tio n o f TNB i n E th e r a t Zero D egrees . . . .

7U

23.

Change o f Vapor P re s s u re w ith Change i n S o lv en t Composi­ t i o n o f a S o lu tio n o f TNB i n T e tra h y d ro fu ra n a t 25*0° . . 75

2U*

Change cf Vapor P r e s s u re w ith Change t i o n o f a S o lu tio n o f TNB i n Toluene

i n S o lv e n t Composi­ at 2 5 * 1 °

76

Change c f Vapor P r e s s u re w ith Change t i o n o f a S o lu tio n o f TNB i n Benzene

i n S o lv e n t Composi­ a t 2 5 .0 ° . . . . . .

77

25. 26.

Change o f Vapor P re s s u re w i t h Change i n S o lv e n t Composi­ t i o n o f a S o lu tio n o f TNB i n Thiophene a t 2 U . 9 ° ................78

27.

B eh av io r o f TNB O b tained from V ario u s S o lv e n ts w ith 50 Mole P e r Cent Am m onia.............................................................. .... .

86

The S o l u b i l i t y o f TNB i n V arious S o lv e n ts as C a lc u la te d by R a o u lt *s Law ..........................................................................

89

S o l u b i l i t y o f TNB i n V arious S o lv e n ts from th e I n te r c e p t o f t h e L in e s f o r S a tu ra te d and U n sa tu ra te d S o lu tio n s . . .

90

30.

E v a lu a tio n o f S o l u b i l i t y D a t a ..................................

91

31*

D ata f o r P r e c i p i t a t i o n E xperim ents i n th e High Vacuum L i n e ................................• • • • •

28* 29.

• • • •

I OU

T ab le 32* B eh av io r i n Vacuum l i n e c f S o lid O btained fro m TNB i n E th e r and Ammonia upon Slow E v a p o ra tio n o f S o lu tio n . . . 33.

108

B eh a v io r i n Vacuum o f S o lid O btained from TNB i n E th e r and Anmonia upon R apid E v a p o ra tio n o f S o l u t i o n ......................

109

3U* B eh a v io r i n Vacuum L ine o f S o lid O btained by Adding T rim ethylam ine t o H e a t- tr e a te d TNB i n E t h e r ..........................

113

35* Change o f T em perature w ith Time B efore and A f te r M ixing TNB and T rim ethylam ine S o l u t i o n s .............................. . . . . .

11?

LIST OF FIGURES F ig u re

Page

1.

S p a c ia l c o n f ig u r a tio n s o f t r i - a lp h a - n a p h th y lb o r o n ........................9

2.

The th r e e - b u lb a p p a ra tu s o f K rause and P o la c k

3.

P re s s u r e -c o m p o sitio n d ia g ra m . B eh av io r ex p ected f o r a s o lu t i o n p h en o m en o n .........................................................

.......................... 23 32

Ij.»

P re s s u re -c o m p o s itio n d iag ram .

D ata fro m T able 5 , Run 2

.

. 32

5.

P r e s s u r e -c o m p o sitio n d iag ram .

D ata from T able 6

................. 3k

6.

P re s s u r e -c o m p o sitio n d iagram .

D ata fro m T ab le 7

. . . . .

7.

Change o f P r e s s u r e v e r s u s tim e f o r f r e s h l y p re p a re d TNB-ammonia a t 8 0 .0 t 0 . 3 ° ......................

3U

...Ii2

8.

A p p aratu s f o r f o llo w in g th e d i s s o c i a t i o n p r e s s u r e s

9.

A p p aratu s f o r f o llo w in g t h e d i s s o c i a t i o n p r e s s u r e s o u ts id e o f vacuum l i n e .......................... . . . . . . . 5 5

10.

. . . .

55

A p p aratu s f o r m a in ta in in g c o n s ta n t te m p e ra tu re b y a b o i l i n g l i q u i d ......................

6k

11.

A p p aratu s f o r s e a lin g ammonia and TNB-benzene t o g e t h e r

12.

Vapor p r e s s u r e v e r s u s m illim o le s o f s o lv e n t f o r s o lu tio n s c o n ta in in g 2 .0 3 m illim o le s o f T N B ................................. 8 1

13. lit.

• • 6U

F la s k f o r s e a lin g TNB and s o lv e n t i n v a c u u m .............................. 9k F la s k w ith TNB and s o lv e n t s e a le d t o manometer f o r v a p o r p r e s s u r e te m p e ra tu re . . ........................................

. . . 9U

15.

A p p aratu s f o r d e te rm in in g t h e s o l u b i l i t y o f TNB i n e th e r

• 97

16 .

C a l o r i m e t e r .....................

115

17 •

A p p aratu s f o r p r e c i p i t a t i o n ex p erim en ts i n th e h ig h vacuum l i n e ...............................

119

C o n trib u tio n from t h e D epartm ent o f C hem istry and Purdue R esearch F o u n d a tio n , Purdue U n iv e r s ity , L a f a y e tte , I n d ia n a

A STUDY OF THE EXISTENCE OF ROTATION ISOMERISM IN TRI-ALPHA-NAPHTHYLBORON AND ITS ADDITION COMPOUNDS1

(1 )

C o n tain s m a te r ia l from Mr. A lex Z l e t z 1s D o c to ra l T h e s is .

By H e rb e rt C. Brown and A lex Z le t z 2

(2 )

R esearch C o rp o ra tio n F e llo w , 19U8-1950.

An i n v e s t i g a t i o n was c a r r ie d o u t by Brown and S u jish i-^ i n o rd e r (3 )

Brown and S u j i s h i , T h is J o u r n a l, 7 0 , 2793 (19U 8).

t o examine t h e b a s e s tr e n g t h o f th e amine s e r i e s NH^, CH-^NHg, (CH^gNH, and (CH^)^N -with th e r e f e r e n c e a c id t r i - a lp h a - n a p h th y lb or on ( h e r e a f t e r TNB).

The p r o p e r t i e s v hich th e y o b serv ed f o r TNB and i t s

a d d itio n compounds w ere d i f f e r e n t th a n th o s e r e p o r te d by K rause and Nobbe. (U)

K rause and Nobbe^ r e p o r te d t h a t TNB i s m o d erately s ta b l e i n

K rause an d Nobbe, B e r. , 6 3 , 93li. (1 9 3 0 ).

a i r , i s m o d e rately s o lu b le i n e t h e r , form s an a d d itio n compound w ith trim e th y la m in e , and c r y s t a l l i z e s w ith two m oles o f b en zen e.

Brown and

S u j i s h i found t h a t TNB i s h ig h ly s t a b l e i n a i r , i s s l i g h t l y s o lu b le i n e t h e r , d o es n o t form an a d d iti o n compound w ith trim e th y la m in e , and c r y s t a l l i z e s w ith one mole o f benzene of c r y s t a l l i z a t i o n .

F u rth erm o re,

th e y found t h a t t h e a d d itio n compounds w ith anmonia and methylam ine show f u g i t i v e m e ltin g p o i n t s , and t h a t f r e s h l y p re p a re d TNB a d d itio n compounds w ith anm onia, m ethylam ine, and dim ethylaraine g iv e h ig h e r d i s s o c i a t i o n p r e s s u r e s th a n sam ples w h ich have been h e a te d a t a h ig h te m p e r a tu re . To a c co u n t f o r t h e s e o b s e rv a tio n s Brown and S u j i s h i s u g g e ste d th e e x is te n c e o f two polym orphic form s o f TNB an d i t s s o l i d a d d itio n compounds.

They a s c r ib e d t h e e x is te n c e o f t h e s e polym orphic form s

t o th e r e s t r i c t e d r o t a t i o n o f t h e a lp h a - n a p h th y l groups about th e carb o n t o b o ro n b o n d s.

F u rth e rm o re , t o a c c o u n t f o r th e d i f f e r e n c e s

i n t h e o b s e rv a tio n s , th e y p ro p o sed t h a t K rause and Nobbe i s o l a t e d th e sy m m e tric a l, l e s s h in d e re d , form w h ile th e y had i s o l a t e d t h e unsyrranetric a l , h in d e re d , form o f TNB.

A ll d if f e r e n c e s i n p h y s ic a l and ch em ical

p r o p e r t i e s c o u ld be e a s i l y accounted f o r i n term s of t h i s sim p le h y p o th e s is . The p r e s e n t w ork was u n d e rta k e n to stucfor th e v a l i d i t y o f t h i s in te rp re ta tio n .

The e x is te n c e o f r o t a t i o n iso m erism i n TNB and i t s

a d d itio n compounds was i n v e s t i g a te d by o b s e rv in g t h e i r b e h a v io r i n s o lu tio n and in t h e s o l i d s t a t e . R e s u lts P re p a ra tio n s .

The p r e p a r a tio n o f TNB by th e p ro c e d u re s o f

Brown and S u j i s h i ^ , and K rause and Nobbe^ was c a r r i e d o u t to compare t h e two p ro d u c ts f o r r e p o r te d d i f f e r e n c e s ^ . and S u j i s h i was u sed e s s e n t i a l l y a s r e p o r te d .

The p ro c e d u re o f Brown T h e ir p ro d u c t, which

i s o b ta in e d by d r iv in g o f f t h e b en zen e from th e s o lv a te , i s r e f e r r e d t o a s h e a t - t r e a t e d TNB.

The p ro c e d u re o f K rause and Nobbe had t o b e m o d ifie d i n o rd e r t o p r e v e n t t h e p r e c i p i t a t i o n o f th e f i n a l p r o d u c t from th e e t h e r s o lu tio n *

T h is was done by r e d u c in g t h e q u a n t i t i e s o f t h e r e a c t a n t s

t o ab o u t o n e - fo u r th w h ile k e ep in g t h e amount o f e th e r th e same.

The

p ro d u c t from t h i s p ro c e d u re was th e n p u r i f i e d i n th e t h r e e - b u l b a p p a ra tu s o f K rause and P o la c k ^ . (5 )

The q u a n t i t i e s o f TNB re c o v e re d

K rause and P o la c k , B e r. $9, 777 (1 9 2 6 ).

by s u c c e s s iv e c o n c e n tr a tio n s o f t h e e t h e r s o lu tio n c o n ta in in g th e p ro d u c t may b e s i g n i f i c a n t .

When 500 m l. of t h e f i n a l e th e r s o lu tio n

was red u ced to 250 m l., 12 g . of TNB was r e c o v e re d . t r a t i o n to 120 m l. y ie ld e d 1 ,7 g . o f TNB.

F u r th e r concenr*

Thus, from t h e f i r s t ev ap o ra­

t i o n one would deduce a s o l u b i l i t y o f 5 g . o f TNB p e r 100 m l. o f s o lu t i o n , b u t o n ly a s o l u b i l i t y o f 1 .3 g . p e r 100 m l. o f s o lu tio n from th e amount o f TNB re c o v e re d i n th e second con c e n t r â t io n .

If

t h e second c o n c e n tr a tio n w ere n o t made, th e s o l u b i l i t y deduced w ould d o u b tle s s be h ig h due t o th e o c c u rre n c e o f s u p e r s a t u r a t i o n . Two sam ples o f h e a t - t r e a t e d TNB were c r y s t a l l i z e d from benzene f o r s tu d y o f th e s o l v a t e .

The TNB-benzene o b ta in e d i n t h i s way

c o n ta in e d a sm a ll e x c e s s ( c a . 6%) o f benzene. The B eh av io r o f TNB and I t s A d d itio n Compounds i n th e S o lid S t a t e . D i f f i c u l t y was e x p e rie n c e d i n g e t t i n g r e p r o d u c ib le d i s s o c i a t i o n p r e s s u re s f o r low p r e s s u r e ( h e a t - a l t e r e d ) TNB-ammonia.

T h is was a t t r i b u t e d to

e i t h e r a s o lu t i o n phenomenon betw een TNB and TNB-ammonia or slow e s ta b lis h m e n t o f e q u ilib r iu m , o r b o th .

A s o lu tio n phenomenon could

be t e s t e d f o r by d e te rm in in g t h e n a tu r e o f th e p re s s u re -c o m p o s itio n

cu rv e a t a g iv e n te m p e r a tu re .

T h is was done by u s in g a m o lar ex cess

o f ammonia to p r e p a r e t h e low p r e s s u r e a d d itio n compound.

A f te r

h e a tin g a t II4.O0 f o r tw e n ty - f iv e h o u rs, th e am nonia was removed p o rtio n w is e and t h e p r e s s u r e s re c o rd e d . I-A*

These a re giv en i n T ab le

The p r e s s u re -c o m p o s itio n cu rv e su g g e ste d a s o lu tio n phenomenon;

how ever, t h e r e s u l t s in d ic a te d t h a t , i f t h i s e x i s t s , i t i s over a v e ry s m a ll c o m p o sitio n r e g io n (one mole p e r cen t o r l e s s ) . T able I D is s o c ia tio n P re s su re-C o m p o sitio n D ata f o r TNB-amnonia a t U4O0 A,

Run No. 1

Mole % nh3 10U.8 1 0 iu 3 103.2 1 0 2 .3 1 0 0 .8 99*6 9 8 .8 9 8 .1 9 7 .0 95.7 9 7 .5

P ress. (ram.) 6 6 .8 6 0 .9 1*7.1 3 6 .5 1 9 .2 9 .2 8 .U 8 .3 8 .2 8 .2 8 .9

B.

Run No. 2

Mole % NH3 10U.8 103.1 1 0 0 .9 1 0 0 . 1* 10 0 .0 99.7 9 8 .6 9 7 .5 91*. 8 9 0 .3 8U.0 71*.0 6 3 .5 5 1 .1 3 8 .2

P re ss, (mm. ) 6 6 .0 1*5 .8 1 9 .2 il*.5 1 0 .U 8.7 5 .3 1*.0 t o 8 .2 8 .5 8 .5 8 .7 8.7 8 .6 8 .6 8 .3

An a tte m p t was t h e n made to d e f in e t h i s sm à ll r e g i o n .

The

ammonia was r e tu r n e d to t h e same sam ple o f TNB and a f t e r te n hours rem oval was s t a r t e d .

T h is tim e an u n u su al phenomenon o c c u rre d .

The

p r e s s u r e d ropped t o a minimum v a lu e a t ab o u t 97*5 p e r c e n t ammonia and t h e n r a p i d l y r o s e t o a c o n s ta n t v a lu e .

These a re re c o rd e d i n

V

T a b le I-B and p l o t t e d i n F ig u re 1 ,

Two r e p e t i t i o n s o f t h e e x p e rim e n t,

le a v in g th e components a t II4.O0 f o r 85 h o u rs showed t h a t t h i s phenomenon was r e p r o d u c ib le , and t h a t th e m inim um o c c u rre d a t ab o u t 97 t o 97 #5 mole p e r

ammonia.

T h is phenomenon co u ld b e e x p la in e d i f h e a tin g f o r a lo n g p e r io d édherêrted §11 t h e TNB t o t h e a d d itio n compound, w h e re a s, h e a tin g f é t a s h o r t tim e , i . e . 25 h o u r s , l e f t some uncombined TNB. Thus, upon rem oving ammonia from th e c o m p le te ly c o n v e rte d s o l i d t h e r e was no TNB a v a i l a b l e t o a c t a s c e n te r s o f c r y s t a l l i z a t i o n .

As a

r e s u l t , TNB accu m u lated u n t i l a s u f f i c i e n t m o u n t was p r e s e n t f o r c r y s t a l l i z a t i o n t o commence. p e r c e n t ammonia.

T h is a p p a r e n tly o c c u rre d a ro u n d 97

P resum ably, when t h e h e a tin g tim e was 25 h ours

c r y s t a l s o f TNB w ere s t i l l p r e s e n t , and t h e l i b e r a t e d TNB was a b le to c r y s t a l l i z e so t h a t no minimum was o b s e rv e d . The b e h a v io r o f h e a t - t r e a t e d TNB w ith ammonia a t 80° was exam ined.

Ammonia, 50 m ole p e r c e n t was added t o th e TNB and th e

ch an g e o f p r e s s u r e w ith tim e r e c o rd e d . T a b le I I - A .

The r e s u l t s a r e g iv en i n

T h is p ro c e d u re was u se d a s a method o f d e te c tin g th e

p re s e n c e o f t h e h y p o th e siz e d iso m er o f h e a t - t r e a t e d TNB.

T h is iso m er

would b e e x p e c te d t o y i e l d low p r e s s u r e TNB-ammonia w hich h a s a z e ro d i s s o c i a t i o n p r e s s u r e a t 80°*

The p ro c e d u re was a p p lie d to

t h e p ro d u c t o b ta in e d from t h e K rause and Nobbe p r e p a r a tio n and r e c i y s t a l l i z e d i n t h e t h r e e - b u l b a p p a ra tu s •

The p r e s s u re change was

s i m i l a r t o t h a t f o r heatfe-treated TNB i n d i c a t i n g no d if f e r e n c e i n th e p ro d u c ts ÇTatolt Î l - B ) .

Pressure — com p osition Data

M O LE

from

PERCENT.

Table

AM M ON I A

diogrom 5

T able I I Change o f P re s s u re Tniith Time o f F re s h ly P re p a re d THB-ammonia a t 80° A,

H e a t- tr e a te d THB and h9 Mole % NH^

Time ( m in .)

3

B.

7 10 lh 18 25 32 13 57 73 82 102 167 198 211 227

2U2

Time ( m in .)

P r e s s , (mm.) 106 65 52 1*2 36 3 0 .1 26.1* 2 3 .0 2 0 .5 1 7 .9 1 7 .6 1 6 .3 1 3 .7 1 2 .8 1 2 .5 1 2 .2 1 2 .1

K rause and Nobbe TNB and 1*8 Mole % NH3 P r e s s , (ram.)

2 3 1* 5 6 8 10 12 17 20

no

135 11*0

81 73 65 59 56 50 1*5.5 1*2.1 3 6 . 1* 31*.1* 2 2 .6 22 .2 18*

* R eading was ta k e n w ith a d ry i c e b a th a t tu b e o u ts id e o f h e a te d area.

An a tte m p t was made t o p re p a re th e iso m er o f h e a t - t r e a t e d TNB i n t h e s o l i d s t a t e .

T his was done t y ad d in g hydrogen c h lo r id e

t o low p r e s s u r e TNB-ammonia•

However, th e r a t e o f p r e s s u r e d e c re a s e

o f t h e hydrogen c h l o r id e o v er th e TNB-ammonia was to o sm all f o r t h i s p ro c e d u re t o be p r a c t i c a b l e . The s o l i d b enzene s o lv a te was s tu d ie d t o d e te rm in e i t s n a tu r e an d t h e n a tu r e o f t h e TNB p re s e n t* o f b en zen e o v er th e s o lv a te were made*

P r e s s u re m easurem ents

The e s ta b lis h m e n t o f

e q u ilib riu m was fo u n d t o b e v e ry slow when approached from e i t h e r d ire c tio n .

T able I I I l i s t s th e e q u ilib riu m p r e s s u r e s a t 2 5 °, a s

o b ta in e d from t h e r e v e r s e d i r e c t i o n , and th e tim e s r e q u ir e d t o r e a c h th e s e p r e s s u r e s w ith change i n t h e mole p e r c e n t o f b e n z e n e .

The

vüi

s h a rp d ro p i n p r e s s u r e i n ch anging t h e c o m p o sitio n fro m i 06 to 96 p e r c e n t d e m o n stra te s th e e x is te n c e o f a 1 :1 compound.

The d e v ia tio n

o f t h e p r e s s u r e s from c o n sta n c y may b e due to la c k of e q u ilib r iu m . T h is r e q u i r e s f u r t h e r s tu d y . T a b le I I I D is s o c ia tio n P r e s s u re s o f TNB-benzene a t 2 5 .0 + 0 . 1°

106

Mole % C5H5

96

87

lh

P re s s u re (mm.)

3 8 .3

2 7 .2

2 6 .8

2 5 .9

Time (D ays) to r e a c h e q u ilib riu m v a lu e

30

30

33

29

The b e h a v io r o f t h e s o l v a t e ■with ammonia was examined to d e te rm in e t h e n a tu r e o f t h e TNB p re s e n t*

When ammonia

was added t o

t h e s o lv a t e , i t was ab so rb ed a t room te m p e ra tu re w ith o u t l i b e r a t i n g benzene*

H e atin g a t 80° l i b e r a t e d t h e b e n z e n e le a v in g lo w p r e s s u r e

TNB-ammonia.

T h is shows t h a t t h e TNB i n t h e s o lv a t e i s d i f f e r e n t from

t h a t i n h e a t - t r e a t e d TNB* The b e h a v io r o f t h e TNB, o b ta in e d by l i b e r a t i n g t h e b en zen e from th e s o lv a t e a t 8 0 °, w as a ls o exam ined. th e b e h a v io r o f t h e r e s id u e w ith ammonia*

T h is was done by s tu d y in g When t h e s o lv a te was h e a te d

a t 80° f o r tw o h o u rs and ammonia added to th e r e s i d u e , th e amount o f low p r e s s u r e TNB-ammonia o b ta in e d in d ic a te d t h a t 83 p e r c e n t o f t h e TNB f r e e d o f benzene was p r e s e n t a s th e low p r e s s u r e TNB-ammonia.

When t h e s o lv a t e was h e a te d a t 80° f o r 53 h o u rs an d ammonia added to th e r e s i d u e , t h e am ount o f low p r e s s u r e TNB-ammonia o b ta in e d in d ic a te d t h a t a b o u t 20 p e r c e n t o f t h e TNB f r e e d o f b en zen e w as p r e s e n t a s t h e low p r e s s u r e TNB-ammonia.

These r e s u l t s d e m o n stra te t h a t t h e n a tu r e

o f t h e TNB l i b e r a t e d from t h e s o lv a t e was d i f f e r e n t from t h a t o f h e a tt r e a t e d TNB, s in c e t h e r e s i d u e r e a c te d w ith anmonia a t room te m p e ra tu re t o g iv e low p r e s s u r e TNB-ammonia.

F u rth e rm o re , a f t e r a p e r io d o f 53

h o u rs a t 80° t h i s r e s id u e had changed t o a f orm w hich was q u ite s i m i l a r t o th e u s u a l h e a t - t r e a t e d TNB. The N atu re o f t h e P ro d u c t O btained by R e c r y s t a l l i z in g H eatt r e a t e d TNB from V ario u s S o lv e n ts and t h e S o l u b i l i t i e s o f TNB. I t was s u s p e c te d t h a t th e e x is te n c e o f t h e b en zen e s o lv a te o f TNB depended on t h e p re se n c e o f h o le s i n th e c r y s t a l l a t t i c e .

H eat-

t r e a t e d TNB w as, t h e r e f o r e , c r y s t a l l i z e d from s e v e r a l s o lv e n ts t o d e term in e i f t h e r e was a r e l a t i o n s h i p betw een t h e s i z e , s h a p e , and co m p o sitio n o f t h e s o lv e n t m o lecu le an d t h e s o lv e n ts a b i l i t y t o form a s o lv a te .

Two p ro c e d u re s w ere u s e d .

I n P ro c e d u re No. 1 a w eighed

amount of TNB was d is s o lv e d i n t h e s o lv e n t and t h e s o lu t i o n was e v a p o ra te d t o d ry n e ss a t t h e red u c e d p r e s s u r e o f a n a s p i r a t o r .

The

s o l i d r e s i d u e w as th e n pumped o u t a t 1 t o 2 mm. cf p r e s s u r e on an o i l pump and t h e r e s i d u e w eighed.

I n P ro ced u re No. 2 w eighed

q u a n t i t i e s o f TNB and s o lv e n t w ere s e a le d i n an e v a c u a te d f l a s k .

The

s o l i d was d is s o lv e d i n t h e s o lv e n t and t h e f l a s k was jo in e d to a manometer on t h e h ig h vacuum l i n e .

The v a p o r p r e s s u r e o f t h e s o lu ti o n

was re c o rd e d a f t e r each rem o v al o f s o lv e n t.

T able IV g iv e s th e r e s u l t s f o r P ro ced u re No. 1 . show t h a t o n ly b enzene and th io p h e n e y i e l d compounds.

The r e s u l t s A ls o , i t i s

a p p a re n t t h a t th e l a s t p o r tio n s o f s o lv e n t a re d i f f i c u l t t o remove from th e TNB by pumping o n ly . T ab le TV D ata on C r y s t a l l i z i n g H e a t- tr e a te d TNB from V ario u s S o lv e n ts b y P ro ced u re No. 1 W t. a f t e r e v a c u a tin g a t 1 t o 2 mm. 1 h r . F u r th e r

S o lv e n t

Wt. o f TUB

W t. of R esid u e a f te r a s p ira tin g t o d ry n e ss

Benzene

2 .068

2.552

2.535

2 .5 3 1 (23 h r s . )

1 .1 3

T oluene

2 .156

2 .2 3 8

2.2 2 0

2.211 (16 h r s . )

0 .1 1

CC1U

2.3U1

3 . 1*60

2.U92

THFa

1 .8 6 8

2.551*b

1 .9 itl

E th e r

0.5U1*

O.6O6

0 .5 8 2

0 .575 (12 h r s . )

0 .3 0

Thiophene

2.1*82

3 .1 0 2

3.013

3.0 0 8 (2 h r s . )

0 .9 8

F ur an

1 .8 8 6

2.011

1.987

1.9 7 8 (2 h r s . )

0.3U

2 . k76 (1 h r . ) —

M oles of s o lv e n t p e r mole o f TNB

0 .1 5 0 .2 1

a.

T e tra h y d ro fu ra n .

b.

T h is r e s i d u e w as a s p i r a t e d f o r 12 h o u rs b e f o r e p la c in g on o i l pump5 t h e w t. a t t h e end o f t h i s tim e was 1 .9 5 2 g. The s o lu tio n o f t h i s s o lv e n t showed a marked ten d en cy to s u p e r s a t u r a t e . The d a t a o b ta in e d by P ro ced u re No. 2 i s p l o t t e d i n F ig u re 2.

I n o r d e r to g e t a l l t h e c u rv e s on one graph ( th e p r e s s u r e s o f th e

SOLVENT OF MILLIMOLES

H

Nonmos aaivynivs jo 3anss3Hd N 3 1 S À S 3 0 3 tin S S 3 tid



s o lv e n ts ra n g e d from 186 mm. f o r e th e r a t z e ro d e g re e s t o 2 8 .5 mm. f o r to lu e n e a t 25 .1 °)> t h e v ap o r p r e s s u re o f th e s o lu t io n was d iv id e d by t h e v ap o r p r e s s u r e o f th e s a tu r a t e d s o lu tio n and p l o t t e d on th e o r d in a te a x i s .

The m illim o le s o f s o lv e n t p r e s e n t i n s o lu tio n

was p l o t t e d as a b s c i s s a .

By t h i s m ethod, t h e r e g io n o f s a t u r a t e d

s o lu tio n s f o r a l l p l o t s f a l l on t h e same l i n e . i d e a l b e h a v io r f o r compound fo rm a tio n .

Curve I r e p r e s e n ts

Curve I I i s t h e p l o t of t h e

d a t a f o r carb o n t e t r a c h l o r i d e , w hich r e p r e s e n t s , v e ry c l o s e l y , th e cu rv es f o r e t h e r , t o l u e n e , and t e tr a h y d r o f u r a n , e x c e p t t h a t t e t r a ­ h y d ro fu ran showed a d ip d u e t o s u p e r s a t u r a t i o n .

Curves I I I and IV

a r e p l o t s o f t h e d a t a f o r b en zen e an d th io p h e n e , r e s p e c t i v e l y .

It

sh o u ld b e p o in te d o u t t h a t w here th e c u rv e s d ro p from t h e h o r iz o n ta l th e r e was no l i q u i d p h a se p r e s e n t i n th e f l a s k .

The v a lu e w here t h i s

o c c u rre d v a r ie d from 6 to 16 m illim o le s of s o lv e n t .

I n th e re g io n

below t h e s e v a lu e s , t h e s o lv e n t p ro b a b ly e x i s t e d i n a s o li d s o l u t i o n . Benzene i s seen t o fo rm a compound, and th e b e h a v io r o f th io p h e n e shows t h e te n d e n c y tow ard canpound fo rm a tio n .

The d e v ia tio n

i n th e th io p h e n e cu rv e i s p ro b a b ly due t o la c k o f e q u ilib riu m d a t a , and, p e rh a p s , a s o l u t i o n phenomenon betw een TNB and th e th io p h e n e s o lv a t e .

Curve IT shows t h a t t h e o th e r s o lv e n ts do n o t form

s o lv a t e s , a lth o u g h s o l i d s o lu t i o n s w ith t h e s o lv e n t w ere p r e s e n t in a l l c a ses. B oth p ro c e d u re s a g re e i n show ing s tr o n g s o lv a t e f o rm a tio n w ith b en zen e, w eaker f o rm a tio n w ith th io p h e n e , and no fo rm a tio n w ith t h e o th e r s o lv e n ts .

B oth p ro c e d u re s show t h a t TNB r e t a i n s

more th a n one m ole of b e n z e n e .

T h is e x c e s s benzene i s , no d o u b t.

xiii

h e ld a s s o l i d s o l u t i o n i n TNB-benzene.

The s o lu ti o n phenomenon

ac c o u n ts f o r t h e s l i g h t e x cess of benzene i n t h e s o lv a te s t h a t w ere p r e p a re d , a n d t h e s h a rp d ro p i n p r e s s u r e i n g o in g fro m 106 t o 96 p e r cen t b en zen e i n t h e s o lv a te . These r e s u l t s i n d i c a t e t h a t th e s i z e and sh a p e o f a m o lecu le a r e p ro b a b ly im p o rta n t, b u t t h a t co m p o sitio n i s u n im p o rta n t•

The

f a i l u r e t o g e t a s o lv a te from to lu e n e and th e d e c re a s in g o rd e r of s o lv a te s t a b i l i t y f o r b e n z e n e , th io p h e n e , an d f u r an can b e i n t e r ­ p r e te d i n te rm s o f t h e d e c r e a s in g s i z e o f t h e s e m o lecu les#

T h is

su g g e sts t h a t th e s t a b i l i t y of t h e s o lv a te depends on th e p re s e n c e o f a s o lv e n t m o lec u le o f j u s t th e r i g h t s i z e t o p e rm it a maximum f i l l i n g o f sp ace i n t h e c r y s t a l , s in c e t h i s would le a d to a minimum p o t e n t i a l energy f o r th e system#

I t j u s t happens t h a t benzene f i t s

th e re q u ire m e n ts b e t t e r th a n any of th e s o lv e n t s s tu d ie d . The fo rm a tio n o f s o lv a te s o n ly by th e " f l a t " a ro m a tic s o lv e n ts su g g e sts t h a t t h e th ic k n e s s o f t h e s o lv e n t m olecule may a ls o be im p o rtan t# I f th e above c o n c lu s io n s on th e dependence o f s o lv a t e fo rm a tio n on s iz e and sh ap e o f s o lv e n t m o lecu les a r e c o r r e c t , th e n t h e r e m ust be h o le s i n t h e TNB c r y s t a l

t o acco u n t f o r t h i s dependence.

A c a l c u l a t i o n o f th e s o l u b i l i t i e s of he a t - t r e a t e d TNB i n v a r io u s s o lv e n ts co u ld be made from th e d a ta o f P ro ced u re No. 2 b y two m eth o d s.

In o n e, R a o u lt' s law was a p p lie d u sin g t h e vapor

p r e s s u r e cf th e s o lv e n t and th e v a p o r p r e s s u r e o f the s a tu r a te d s o lu tio n #

In t h e o t h e r , t h e I n te r c e p t o f th e l i n e s fo r s a tu r a t e d

and u n s a tu r a te d s o lu tio n s was u s e d .

The co m b in atio n o f th e two

v a lu e s o b ta in e d b y t h e s e m ethods, in c lu d in g any o v e rla p p in g i n

xiv

t h e v a l u e s , i s g iv e n i n T ab le V f or each s o lv e n t* T able V The S o l u b i l i t i e s of H e a t- tr e a te d TNB as C a lc u la te d from t h e D ata o f P ro ced u re No. 2 S o lv e n t

Temp.

g. TNB p e r 100 g . o f s o ln .

c c iu

2 5 .0

8.L ± 1 .2

T e tra h y d ro fu ra n

25.0

23 t 2

Benzene

2 5 .0

6 .2 Î 1 .2

Toluene

25.1

13 £ 3

0 .0

E th e r Thiophene

2U.9

1 .0 * 0 .3

25 t 5

A more p r e c i s e v a lu e f o r th e s o l u b i l i t y o f h e a t - t r e a t e d TNB i n e th e r was c a l c u l a t e d from th e r e s u l t s o f ex p erim en ts i n th e vacuum lin e .

T h is v a lu e was 0 .9 0 i 0*06 g. p e r 100 g . o f s o lu t i o n . The s o l u b i l i t y o f t h e r e c r y s t a l l i z e d K rause and Nobbe TNB

was d e te rm in e d b y e v a p o r a tin g th e e t h e r from a s a tu r a te d s o lu tio n o f t h e TNB i n a known w e ig h t o f e t h e r . was u sed t o c a l c u l a t e t h e s o l u b i l i t y . 1 .0 ? g* p e r 100 g. o f s o l u t i o n .

The w eig h t o f th e r e s i d u a l s o lid T his was d eterm in e d t o b e

T his v a lu e was p ro b a b ly h ig h due

t o t h e d i f f i c u l t y o f rem oving th e l a s t p o r tio n s o f a d h e rin g s o lv e n t ( s e e T a b le IV ). The B eh av io r o f TNB and I t s Benzene S o lv a te i n S o lu tio n . Gaseous ammonia was added t o ether* s o lu tio n s of h e a t - t r e a t e d TNB, and TNB from t h e K rause and Nobbe p ro c e d u re .

N e ith e r s o lu tio n

y ie ld e d a p r e c i p i t a t e even a f t e r s ta n d in g f o r a t l e a s t one day.

XV

A f te r a n e t h e r s o lu t i o n o f h e a t - t r e a t e d TNB was s a tu r a t e d w ith ammonia and a s p i r a t e d t o d r y n e s s , th e r e s id u e was low p r e s s u r e TNB-ammonia»

When a f r e s h sam ple o f h ig h p r e s s u r e TNB-ammonia was

d is s o lv e d i n e t h e r and th e s o lv e n t r a p i d l y rem oved, th e low p r e s s u r e form o f TNB-ammonia was o b ta in e d . from t h e s e r e s u l t s .

Two c o n c lu s io n s c an b e reach ed

F i r s t , t h e r a t e o f is o m e r iz a tio n o f th e h ig h

p r e s s u r e to t h e low p r e s s u r e form o f TNB-ammonia m ust b e r a p id i n s o lu t i o n , even a t o rd in a ry te m p e r a tu r e s .

Second, h ig h p r e s s u r e

TNB-ammonia m ust be m e ta s ta b le w ith r e s p e c t to low p r e s s u r e TNBammonia. E th e r s o lu tio n s o f h e a t - t r e a t e d TNB and TNB frcm th e K rause and Nobbe p ro c e d u re were found t o g iv e p r e c i p i t a t e s upon a d d itio n cf trim eth y lam L n e,

However, when trim e tty la m in e was added t o s o lu tio n s

o f h e a t - t r e a t e d TNB and t h e b enzene s o lv a te i n c a r e f u l l y d r ie d e th e r , no p r e c i p i t a t e was o b ta in e d .

E xperim ents showed t h a t l i t t l e i f any

com bination o c c u rre d b etw een TNB and th e amine a t zero d e g r e e s . F u rth erm o re, p r e c i p i t a t i o n to o k p la c e o n ly when w a te r was added to th e e th e r s o lu t i o n s .

The w a te r, trim e th y la m in e and TNB w ere d eterm in e d

a s com bining i n m olar r a t i o s .

The compound m e lte d around 16U° i n an

e v a c u a te d c a p i l l a r y tu b e , b u t a t u r b i d i t y p e r s i s t e d even a t 210°. The r e s u l t s show t h a t TNB i s too h in d e re d f o r th e n itr o g e n t o g e t s u f f i c i e n t l y c lo s e t o t h e b o ro n f o r bond fo rm a tio n .

Presum ably,

trim ethylam m onium h y d ro x id e i s form ed i n th e p re se n c e o f w a te r , and th e h y d ro x y l io n can r e a d i l y add t o t h e boron atom . The benzene s o lv a te and h e a t - t r e a t e d TNB i n e th e r s o lu tio n showed s i g n i f i c a n t d if f e r e n c e s i n b e h a v io r .

The ex p erim en ts w ith

x v i

th e s e compounds w ere c a r r i e d out i n th e vacuum l i n e u s in g t r i m e t t y l amine and a s o lv e n t t h a t c o n ta in e d a sm all amount of w a te r .

The

a d d itio n o f t h e trim e th y la m in e to t h e s o lu tio n s o f TNB and TNBb enzene i n t h e Mw et" e th e r s o lv e n t gave p r e c i p i t a t e s .

However,

t h e TNB i n t h e form o f th e benzene s o lv a te c r y s t a l l i z e d a b o u t tw ic e as r a p i d l y a s t h e TNB i n th e h e a t - t r e a t e d fo rm . g iv e n i n T ab le V I.

The r e s u l t s a re

These r e s u l t s d e m o n stra te th e p re se n c e o f a

d i f f e r e n t form o f TNB i n t h e s o lv a te th a n i n h e a t - t r e a t e d TNB. T ab le VI Time R eq u ire d f o r a P r e c i p i t a t e to Appear i n "Wet" E th e r S o lu tio n upon A d d itio n o f T rim ethylam ine

Compound

Wt. o f Sample

Mole % of Amine

Time ( ra in .) when p p tio n began

TNB

.0790

1 0 2 .8

35

TNB

.079b

1 0 9 .9

32

tnb . c6H6

.0972

1 0 1 .5

16

T N B -C ^

.0958

1 0 6 .6

15

D is c u s s io n of R e s u lts The stu d y o f t h e e x is te n c e of r o ta tio n isom erism i n TNB h in g ed on t h e p r e p a r a tio n of th e two h y p o th e siz e d c r y s t a l l i n e form s o f t h i s compound and t h e e x a m in atio n o f t h e i r p r o p e r t i e s i n s o lu tio n and i n th e s o l i d s t a t e .

The r e p o r te d d i f f e r e n c e s i n t h e p ro d u c ts o f

K rause and Nobbe, and Brown and S u j i s h i l e d to th e u se o f t h e i r d i f f e r e n t m ethods o f p r e p a r a tio n .

The two p r e p a r a tio n s w ere e x p e c te d t o

d i f f e r i n t h e i r s o l u b i l i t i e s i n e t h e r , in t h e i r b e h a v io r upon

a d d itio n of ammonia to th e s o l i d s and t h e i r s o lu t i o n s , and i n t h e i r b e h a v io r i n s o lu t i o n upon a d d itio n o f trim e th y la m in e . o f t h e s e d i f f e r e n c e s m a t e r ia li z e d .

However, none

The s o l u b i l i t i e s o f t h e two

p r e p a r a tio n s w ere th e same3 t h e i r b e h a v io r upon a d d i t i o n o f ammonia t o t h e s o l i d s and t h e i r e th e r s o lu tio n s r e v e a le d no d i f f e r e n c e s ; and th e y showed no d i f f e r e n c e i n t h e i r b e h a v io r w ith trim e th y la m in e i n e t h e r s o lu t i o n . The e x is te n c e o f two form s o f TNB-ammonia, one m e ta s ta b le w ith r e s p e c t t o th e o th e r , s u g g e s ts t h e same phenomenon f o r TNB* I f one fo rm o f TNB w ere m e ta s ta b le w ith r e s p e c t t o th e o t h e r , th e n o n ly t h e s t a b l e form would b e o b ta in e d frcm s o lu tio n u n d e r o rd in a ry c o n d itio n s • The d i f f e r e n c e s i n p r o p e r t i e s r e p o r te d b y K rause and Nobbe, and th o s e r e p o r te d h e re and by Brown an d S u j i s h i i s n o t c l e a r l y re s o lv e d .

K rause and Nobbe e i t h e r , somehow, i s o l a t e d a v e ry u n s ta b le

fo rm o f TNB, o r t h e y w ere w rong i n t h e i r o b s e rv a tio n s on s o l u b i l i t y , m oles o f benzene o f c r y s t a l l i z a t i o n , and t h e a c t u a l p ro d u c t o b ta in e d upon r e a c t i o n w ith trim e th y la m in e .

F u r th e r work on th e G rig n ard

r e a c t i o n may h e lp t o c l a r i f y th e p ro d u c t t h a t can a c t u a l l y b e i s o l a t e d by t h i s m ethod.

As t h e c a s e now s ta n d s , th e u s e o f d if f e r e n c e s

i n p r o p e r t i e s o f t h e p ro d u c ts f o r th e h y p o th e s is o f r o t a t i o n iso m erism i n TNB i s n o t v a l i d . However, t h e w ork on t h e b e n zen e s o lv a te s u p p o rts th e hypo­ t h e s i s o f r o t a t i o n iso m erism in TNB.

The b e h a v io r o f t h e s o lv a te

w ith ammonia showed t h a t th e TNB p r e s e n t i n th e s o l v a t e , and t h e TNB f r e s h l y l i b e r a t e d fro m t h e s o lv a t e by d r iv in g o f f benzene w ere

d i f f e r e n t from h e a t - t r e a t e d TNB.

T his d if f e r e n c e p e r s i s t e d i n th e

s o l u t i o n , u s in g a w et e t h e r s o lv e n t, when t h e TNB i n t h e fo rm o f t h e s o lv a te gave a p r e c i p i t a t e tw ice a s r a p i d ly a s h e a t - t r e a t e d TNB upon a d d itio n o f trim e th y la m in e .

I t i s c o n c e iv a b le t h a t t h e d i f f e r e n c e

i n r e a c t i v i t y o f t h e s e tw o s u b s ta n c e s co u ld b e due t o d i f f e r e n t n

o r ie n ta ti o n s o f t h e m o le c u le s i n th e c r y s t a l s su ch t h a t r e a c t i v e c e n te r s a r e exposed i n one c a s e b u t n o t i n t h e o th e r .

However, th e

b e h a v io r o f such s o l i d s i n s o lu t i o n would b e in d e p e n d e n t of t h e c r y s t a l l i n e c o n f ig u r a tio n s , and t h e tw o s o lu t i o n s would behave s im ila r ly .

I n t h e p r e s e n t c a s e , t h e TNB i n th e s o lv a te and i n th e

h e a t - t r e a t e d fo rm showed d if f e r e n c e s b o th i n th e s o l i d s t a t e and i n s o lu t i o n , hence t h e r e a c t i n g TNB m o le c u le s m ust b e d i f f e r e n t .

T h is

d i f f e r e n c e i s s t i l l e a s i l y a cco u n ted f o r b y r o t a t i o n iso m erism . E x p e rim e n ta l D e t a i l s M a te r i a l s .

The p r e p a r a tio n o f ammonia and trim e th y la m in e

h as b e e n p r e v io u s ly d e s c rib e d ^ . (6 )

Brown, B artholom ay, and T a y lo r, T h is J o u r n a l, 6 6 , 1*35 (19UU). Hydrogen c h l o r id e , o b ta in e d from a com m ercial ta n k o f t h e

anhydrous m a t e r i a l , was condensed w ith l i q u i d n itr o g e n and th e m iddle f r a c t i o n condensed i n t h e h ig h vacuum l i n e .

T h is was th e n

p a s se d th ro u g h s e v e r a l t r a p s a t - 8 0 ° , and th o ro u g h ly pumped o u t. F re s h ly d i s t i l l e d an h y d ro u s e th e r was th o ro u g h ly pumped o u t i n t h e vacuum l i n e .

One sample was s t o r e d , w h ile a n o th e r was

d r ie d o v er sodium and a g a in pumped o u t. "w et" s o lv e n t.

The f i r s t sam ple was t h e

O th er in te r m e d ia te s u sed w ere Eastm an Kodak Compary o r du P ont Company p ro d u c ts an d w ere p u r i f i e d by s ta n d a rd methods* P re p a ra tio n s *

The Brown and S u jis h i^ p ro c e d u re f o r p r e p a r in g

TNB was m o d ifie d s l i g h t l y *

I t was fo u n d e a s i e r t o h a n d le t h e s o l i d

a f t e r h y d r o ly s is i f t h e o rg a n ic an d in o r g a n ic m a te r ia ls w ere s e p a ra te d b e f o r e r e c r y s t a l l i z a t i o n o f t h e crude p r o d u c t.

T h is was done b y

h y d ro ly z in g t h e e th e r-b e n z e n e s o l u t i o n i n a 2 - 1 . s e p a r a te ly f u n n e l, r a t h e r t h a n i n a f l a s k , and rem oving t h e low er l a y e r o f in o rg a n ic m a te ria ls .

The u p p e r la y e r was p la c e d i n a f l a s k w hich was l e f t

i n a r e f r i g e r a t o r o v e r n ig h t.

The s o li d re c o v e re d frcm t h i s s o l u t i o n ,

on a Buchner f u n n e l (w ith f i l t e r p a p e r ) , was t r e a t e d f u r t h e r by t h e i r p ro c e d u re . The m o d ifie d K rause and Nobbe P ro c e d u re c o n s is t e d o f th e r e a c t i o n o f 7*3 g. ( 0 .3 0 g . atom ) o f magnesium w ith ^2 m l. o f a lp h a brom onaphthalene (0*30 m o les) i n a t o t a l of 350 m l. o f e t h e r .

Boron

t r i f l u o r i d e - e t h e r a t e , 8 m l. ( l / l 6 m o le s ), i n 150 m l. o f e t h e r , was added t o t h i s s o l u t i o n , and th e r e s u l t i n g s o lu t i o n ( c o n s i s t i n g o f two l a y e r s ) was h y d ro ly z ed b y a d d in g w a te r t o t h e r e a c t i o n f l a s k . The e t h e r s o lu tio n was p o u red o f f from th e g e la tin o u s r e s i d u e th ro u g h a s i n t e r e d g la s s f u n n e l and c o n c e n tra te d s u c c e s s iv e ly a t red u ced p re ssu re .

The f i n a l p ro d u c t w eighed 13*8 g . (52 p e r c e n t o f th e

th e o re tic a l).

Some o f t h i s p ro d u c t was c r y s t a l l i z e d i n t h e 3 -b u lb

a p p a ra tu s o f K rause and P o la c k ^ . The B eh av io r o f TNB and I t s A d d itio n Compounds i n t h e S o lid S ta te .

P r e s s u re m easurem ents on TNB-ammonia and t h e benzene s o lv a t e ,

t h e r e a c t i o n s o f t h e s o lv a t e w ith anm onia, and t h e a d d itio n o f

3QC

hydrogen ch lo rid e to fN B -w ionis were e a rn e d out v tth th e apparatus shown i s É ls- 7 o f th e paper Tsgr Brown and S ujishi-3» This apparatus was m o d ifie d b y s e a l i n g a g l a s s tu b e t o th e h o r iz o n ta l g la s s arm ::X ;; c o n n e c tin g t h e manometer and t h e r e a c t i o n b u lb » The t u b e c o u ld b e u se d t $ condense t h e l e s s v o l a t i l e v a p o rs frc m t h e g a s p h a s e . J

'

\

'' v

V;:'

.

o f S e a t - t r e a t e d TKB from V ario u s S o lv e n ts

and No. 1»

of T #»

fa); C ry sta lliz a tio n o f TNB by l¥ocedare

; T ^ r - ............................... I& a ^O-fiü.» rouM -botfepm ed lo n g n eck f l a s k w ere w eighed TNB

and a o l v é k t ^ Thé TNB was disse^ared b y warming t h e s o lv e n t, and th e s o lu t i o n w as e v a p o ra te d t o d iÿ n e s s on a w a te r a s p i r a t o r .

The f l a s k

was t h e n e v a c u a te d a t X t o 2 mm. by a n o i l pump^ an d t h e r e s id u e was w eig h ed . (b )

G r y s ta H iz a ld c n b y P ro c e d u re No. 2»

w ere w^gghed i n t h e f l a s k shown i n F ig u re 3 .

TNB and s o l v ^ i t

The s o lv e n t was c o o le d

by a l i q u i d n i tr o g é n b a t h , t h e f l a s k e v a c u a te d t o ICT^ ma. th ro u g h tu b e .as and tu b e a was s e a le d u n d e r vacuum#

The TNB was d is s o lv e d

by w arning th e s o lv e n t a n d t h e r e s u l t i n g « s o la tio n a U sire d t o s ta n d one dz&i Jak i r o n ro d w as p la c e d i n tu b e b> and t h i s tu b e was s e a le d t o a manometer o n t h e vacuum l i n e . m agnet h a d d ro p p e d so a s t o b re a k c .

The i r o n r o d was r a i s e d b y a The f l a s k w as su rro u n d ed b y

a c o n s ta n t te m p e r a tu re b a t h and v a p o r p r e s s u r e r e a d in g s w ere made a s s o lv e n t was rem oved fro m t h e f l a s k t o th e h ig h vacuum l i n e .

The

f i r s t p o rW |# # r s # s o lv e n t removed c o n ta in e d a i r . These w ere -;;V W Y v th o ro u g h ly pumped o u t. P r e s s u re r e a d in g s , on a s o lu tio n w ere n o t made u n t i l t h e p r e s s u r e o f t h e r e c o v e re d s o lv e n t, a t l i q u i d n itr o g e n

sealing

TNB

te m p e r a tu re , was l e s s th a n 10"^ mm. on t h e McLeod Gauge.

Vapor

p r e s s u r e s o f t h e re c o v e re d s o lv e n ts were d e te rm in e d f o r u s e i n c a l c u l a t i n g t h e s o l u b i l i t y by R a o u lt1s law . (c )

The S o l u b i l i t y o f t h e K rause and Nobbe TNB i n E th e r .

The a p p a ra tu s shown i n F ig u re I* was u sed f o r t h i s e x p e rim e n t. TNB, 0 .7 0 3 g . , o b ta in e d frcm th e p u r i f i c a t i o n i n t h e 3 -b u lb a p p a r a tu s , was p la c e d i n b u lb A.

The f l a s k was co n n ected to t h e h ig h vacuum

l i n e by t h e b a l l j o i n t and e v a c u a te d .

Dry e t h e r , 18.81 g . , was

condensed on t h e TNB and th e tu b e a was s e a le d o f f from th e l i n e . The e th e r and TNB w ere l e f t a t 25° f o r one h o u r.

Bulb A was th e n

p la c e d i n an ic e - w a te r b a th , and a f t e r f i f t e e n hours th e e n t i r e a p p a ra tu s was immersed i n t h e b a t h .

A fte r tw e n ty m in u te s th e

a p p a ra tu s was rem oved, and q u ic k ly in v e r te d and r e tu r n e d to th e ic e - w a te r b a t h .

The p a r t o f b u lb A t h a t d id n o t c o n ta in s o lu tio n

was l e f t o u t o f t h e b a t h so t h a t th e s o lu ti o n would b e f o r c e d th ro u g h th e s i n t e r e d g la s s d i s k . i n t h e lo w er b u lb B.

A fte r one h o u r a l l o f th e s o lu tio n was

T h is s o lu tio n was v e iy c l e a r .

The tu b e a was

s e a le d t o t h e tu b e b re a k e r on th e vacuum l i n e , th e t i p of th e tu b e was b ro k e n , and t h e e th e r was slo w ly t r a n s f e r r e d t o t h e l i n e .

When

a l l t h e e th e r had b een d i s t i l l e d o u t, th e a p p a ra tu s was pumped a t 10“ ^ mm. f o r 0 .5 h o u r s .

The tu b e a was c u t from t h e tu b e b r e a k e r ,

and b u lb B was c u t from t h e f i l t e r d i s k . b e fo re and a f t e r w ashing out th e s o l i d .

The f l a s k was th e n w eighed The s o l i d w eighed 0 .203 g .

T here was 0 .0 6 g . o f e th e r i n t h e f r e e space of th e a p p a r a tu s , hence 1 8 .7 5 g* d is s o lv e d t h e TNB. p e r 100 g . o f s o lu t i o n .

The s o l u b i l i t y was, t h e r e f o r e , 1 .0 7 g .

ermlning eth er

th e solubility

xxiv

The B eh av io r of TNB and I t s Benzene S o lv a te i n S o lu tio n . ( a ) Time of P r e c i p i t a t i o n .

F ig u re 5 shows t h e a p p a ra tu s u s e d .

F lo a t

v a lv e a co n n ected th e h ig h vaccum l i n e and th e c a l i b r a t e d m easuring b u lb b .

F lo a t v a lv e c connected

t h e m easu rin g b u lb and t h e r e a c t i o n

sy stem .

The sam ple of TNB (o r TNB-benzene) was w eighed i n t o t h e

b u lb (fro m a 25-m l ro u n d -b o ttom ed f l a s k ) o f f l a s k d w hich was th e n jo in e d to t h e vacuum l i n e by a lU /35 s ta n d a r d - ta p e r j o i n t f t h a t was p r o te c te d b y a m ercury s e a l e . v a lv e c was c lo s e d .

When th e sy stem had b een e v a c u a te d ,

E th e r was th e n m easured o u t i n b a t zero d e g re e s

and v a lv e a was c lo s e d .

Valve c was opened and th e e t h e r was

condensed on t h e TNB w ith d ry i c e .

A f te r co m pletion o f t h i s t r a n s f e r ,

v a lv e c was c lo se d and t h e d ry i c e b a th rem oved.

When th e e t h e r had

warmed to room te m p e ra tu re , t h e e le c tro m a g n e t h , w hich o p e r a te d th e s t i r r e r g, was a c t i v a t e d b y a n o n - o ff r e l a y u n i t .

"While th e TNB was

d is s o lv in g i n e t h e r , trim e th y la m in e was m easured o u t and p la c e d i n b u lb b .

V alve a was c lo s e d and th e amine v a p o r iz e d .

A f te r th e TNB

had d is s o lv e d an d th e s o lu t i o n had b e e n c o o le d to z e ro d e g r e e s , th e v a lv e c was lo w ered a n d th e amine allow ed t o b u b b le th ro u g h th e m ercu ry .

T h is to o k l e s s th a n t h i r t y se c o n d s.

V alve c was th e n r a i s e d ,

v a lv e a was lo w ered and th e r e s i d u a l amine re c o v e re d and m easured. The d if f e r e n c e b etw een t h e two volume m easurem ents on th e amine gave t h e volume o f amine added.

The b u lb o f f l a s k d was k e p t i n an

ic e - w a te r b a t h and observ ed p e r i o d ic a l ly f o r t h e app earan ce o f a p r e c ip ita te . Two ex p erim en ts p e r m itte d a c a lc u la tio n o f s o l u b i l i t y .

In

one case 0.0919 g. of TNB d id n o t d is s o lv e in 9.UU g . o f e th e r , hence

xxvi

th e maximimi s o l u b i l i t y i s 0 .9 6 g . p e r 100 g . o f s o lu t i o n . a n o th e r c a se 0.0800 g . d id d is s o lv e i n

In

g . o f e th e r , hence th e

minimum s o l u b i l i t y i s 0.8U g . p e r 100 g . o f s o lu t i o n .

The s o l u b i l i t y

ca n , t h e r e f o r e , b e giv en §s 0 .9 0 "t 0 .0 6 g . p e r 100 g . of s o lu t i o n a t zero d e g r e e s . (b )

The S t a b i l i t y o f T l^ tr im e th y la x a in e .

Trim e t hy l a n in e was

added to an e th e r s o lu t i o n o f TNB k e p t a t z e ro d e g re e s i n f l a s k d (F ig u re h)*

The v o l a t i l e m a t e r ia ls ( e t h e r and am ine) w ere t r a n s f e r r e d

t o a f l a s k c o n ta in in g an ex cess o f s ta n d a r d a c i d .

The u n r e a c te d

a c id was b a c k t i t r a t e d w ith s ta n d a rd b a s e , and t h i s was used to c a l c u l a t e th e amount o f am ine r e c o v e re d .

A b la n k was ru n on t h i s

p ro c e d u re u s in g o n ly e th e r and trim e th y la m in e .

The r e s u l t s o f two

d e te rm in a tio n s g av e 3 and 7 p e r c e n t, o f th e t h e o r e t i c a l amount, o f amine as re m a in in g w i t h t h e THE. (c) w ith THE.

The P ro p o rtio n s o f T rim ethylam ine and W ater w hich Combine A m o lar amount o f w ater and alm o st tw ic e m olar amount of

amine w ere added to an e t h e r s o lu t io n o f TNB i n f l a s k d .

The v o l a t i l e

m a te r ia ls w ere t r a n s f e r r e d t o a s to r a g e b u lb , and f l a s k d was rem oved, c le a n e d , and d r i e d .

Some calciu m h y d rid e was th e n p la c e d i n th e

f l a s k w hich was r e tu r n e d t o th e l i n e and th o ro u g h ly pumped o u t . e th e r s o lu t i o n was condensed on t h e c a lc iu m t y d r i d e . hydrogen l i b e r a t e d gave t h e amount of u n re a c te d w a te r .

The

The amount o f The hydrogen

was th e n rem oved from th e e th e r by pumping a t -3.96° , an d th e u n re a c te d amine was d ete rm in e d as i n b above.

A b la n k d e te rm in a tio n on w a te r

showed t h a t t h e amount o f w a te r v ap o r m easured i n th e l i n e was g r e a te r th a n t h a t g iv e n by t h e i d e a l gas la w c a l c u l a t i o n .

The amount of

w a te r and trim e th y la m in e t h a t r e a c te d w ith th e TNB was 91 and 9h p e r c e n t, r e s p e c t i v e l y .

The v a r ia n c e from 100 p e r c e n t i s p ro b a b ly

due t o t h e c o m b in atio n o f e r r o r s a r i s i n g i n volume m easurem ents and q u a n t i t a t i v e d e te r m in a tio n s .

Summary P r e p a r a tio n s u s in g t h e p ro c e d u re s o f Brown and S u j i s h i , and K rause and Nobbe d id n o t y i e l d d i f f e r e n t c r y s t a l l i n e form s o f TNB a s e x p e c te d .

The p r o p e r t i e s o f t h e i s o l a t e d p ro d u c ts w ere t h e same.

D if fe r e n c e s i n t h e b e h a v io r o f t h e benzene s o lv a te of TNB and h e a t - t r e a t e d TNB, b o th i n t h e s o l i d s t a t e an d i n s o lu tio n , i n d i c a t e t h e e x is te n c e o f tw o form s o f TNB.

The e x is te n c e o f t h e s e

form s i s e a s i l y i n t e r p r e t e d by r o t a t i o n iso m erism .

A STUDY OF THE EXISTENCE ΠROTATION ISOMERISM IN TRI-ALPHA-NAPHTHYIiBQRON AND ITS ADDITION COMPOUNDS

CHAPTER I INTRODUCTION S ta te m e n t o f Problem The l i t e r a t u r e r e c o rd s t h e p r e p a r a tio n and p r o p e r t i e s o f a number o f t r i a r y l b o r o n s and t h e i r a d d itio n compounds •

Brown and

S u j i s h i (5 ) chose t r i - a lp h a - naphthylboron"*" a s th e r e f e r e n c e a c id f o r t h e i r s tu d i e s o f s t e r i c e f f e c t s .

I n th e c o u rs e o f t h e i r

i n v e s t i g a t i o n t h e y o b serv ed d i f f e r e n t p r o p e r t i e s f o r TNB th a n th o s e r e p o r te d b y K rause and Nobbe ( 1 6 ).

Brown and S u j i s h i found t h a t

TNB c r y s t a l l i z e s w ith one mole o f b en zen e o f c r y s t a l l i z a t i o n ; TNB i s o n ly s l i g h t l y s o lu b le i n e th e r ; i t i s ex tre m e ly s ta b le i n a i r ; i t s a d d itio n compounds w ith ammonia and m ethylam ine show f u g i t i v e m e ltin g p o i ü t s ; f r e s h l y p re p a re d TNB a d d itio n compounds w ith ammonia, m ethylam ine, and d im etbylam ine g iv e h ig h e r d i s s o c i a t i o n p r e s s u r e s th a n sam ples w hich have b e e n h e a te d a t a h ig h te m p e ra tu re ; and TNB does n o t fo rm an a d d itio n compound w ith trim e th y la m in e . On th e o th e r h an d , K rause and Nobbe r e p o r te d t h a t TNB c r y s t a l l i z e s w ith two m oles o f b en zen e o f c r y s t a l l i z a t i o n , i s m o d e ra te ly s o lu b le i n e t h e r , i s m o d e ra te ly s t a b l e i n a i r , and form s an a d d itio n compound

1

F o r b r e v i t y , tr i- a lp h a - n a p h tb y lb o r o n w i l l h e r e a f t e r b e r e f e r r e d to a s TNB.

2

■with trim e th y la m in e •

They d i d n o t m en tio n f u g i t i v e m e ltin g p o i n t s ,

and d i d n o t stu d y d i s s o c i a t i o n p r e s s u r e s . To acc o u n t f o r t h e s e d i f f e r e n c e s Brovm. an d S u j i s h i su g g e ste d th e e x is te n c e o f two polym orphic form s o f TNB and i t s s o l i d a d d itio n compounds.

They a s c r ib e d t h e e x is te n c e o f th e s e polym orphic form s

to th e r e s t r i c t e d r o t a t i o n o f th e a lp h a -n a p h th y l groups about th e carb o n t o b o ro n bonds* The p r e s e n t r e s e a r c h was u n d e rta k e n t o s tu d y t h e e x is te n c e o f r o t a t i o n isom erism i n TNB and i t s a d d itio n compounds. A L i t e r a t u r e Survey o f t h e T r ia r y lb o ro n s and T h e ir A d d itio n Compounds The f i r s t s u c c e s s f u l p r e p a r a tio n o f t h e t r i a r y l b o r o n s and t h e i r a d d itio n compounds was d e s c r ib e d by K rause and Nobbe i n 1922. From th e n th ro u g h 1931 K rause and h i s cow orkers d e s c rib e d s i x t r i ­ a ry lb o ro n s and t h e i r a d d itio n compounds.

A lthough th e s e p r e p a r a tio n s

have b een r e p o r te d b y o th e r w o rk e rs, no one e ls e h as r e p o r te d any new members o f t h e s e r i e s .

N eg ativ e r e s u l t s w ere rep o rted , by

B ent and Dorfman (1 2 ) f o r t h e p r e p a r a tio n o f tr ia n th r a c y lb o r o n .

A

l i s t o f t r i a r y l b o r o n s a n d t h e i r a d d itio n compounds w ith r e f e r e n c e s t o t h e i r p r e p a r a tio n s an d p r o p e r t ie s i s g iv en i n T able 1 .

T rib e n z y l-

b o ro n i s in c lu d e d s in c e i t shows p r o p e r t i e s o f b o th a r y l - and a lk y lb o ro n s . A g e n e ra l method f o r p r e p a r in g t h e t r ia r y lb o r o n s c o n s is t s o f t r e a t i n g an e x c e ss o f t h e a r y l magnesium h a l i d e , p re p a re d i n th e u s u a l m anner, w ith b o ro n t r i f l u o r i d e i n a n it r o g e n a tm o sp h ere. e t h e r s o lu tio n i s th e n r e f l u x e d f o r a few h o u rs .

The r e s u l t i n g

K rause and cow orkers

3

T a b le 1

A l i s t o f T r ia r y lb o ro n s a n d T h e ir A d d itio n Compounds ■with R e fe re n c e s t o t h e L i t e r a t u r e

T riarylboron

Base o r M etal w ith •which A d d itio n Compound I s Formed

Tr iphenyTb o r on

Ammonia, m ethylam ine, e th y l am ine, n -p ro p y la m in e , d im etb y lam in e, tr im e th y la m in e , a n i l i n e , p y r id in e , q u in o lin e , q u in a id ! n e , p i p e r id i n e , p h e n y lh y d ra z in e , N -m o n o e th y la n ilin e , N -d im e th y la n ilin e , dip h en y lam in e ( 1 3 ) , lit h iu m , sodium ( 1 2 ,1 8 ) . p o ta ssiu m , ru b id iu m , cesium ( 1 8 ) , and sod tn d d e ( lU ) .

(15,18)

T ri-p -to ly lb o ro n (1 9 )

Ammonia, p y r id in e , p ip e r id i n e , and sodium ( 1 9 ) .

T rib e n z y lb o ro n (1 6 )

Ammonia, m ethylam ine, trim e th y la m in e , p y r id in e , p i p e r i d i n e , sodium , and lith iu m ( 1 6 ) .

T ri-p -x y ly lb o ro n (1 6 )

Ammonia, m ethylam ine, trim e th y la m in e , p y r id in e , p i p e r i d i n e , and sodium ( 1 6 ) .

T r i- a lp h a naphthyl-boron (1 6 )

Ammonia, m ethylam ine, trim e th y la m in e , p y r id in e , p i p e r i d i n e , and sodium ( 1 6 ) .

T ri-p -a n is y lb o ro n (1 7 )

Ammonia, p y r id in e , and sodium ( 1 7 ) .

h

d ev elo p ed two m ethods f o r i s o l a t i n g th e p r o d u c t a f t e r r e a c h in g t h i s p o in t;

I n t h e e a r l i e r p ro c e d u re t h e e t h e r was removed a t atm o sp h eric

p r e s s u r e , and t h e campound was d i s t i l l e d d i r e c t l y from t h e s o l i d mass o f magnesium s a l t s a t low p r e s s u r e s i n an atm osphere o f n i tr o g e n .

The

l a t e r p ro c e d u re u sed b o i l e d w a te r to h y d ro ly z e t h e magnesium s a l t s . The e t h e r s o lu t i o n was th e n fo rc e d o u t o f t h e f l a s k b y means o f n i t r o g e n , t h e s o lu t i o n w as c o n c e n tr a te d , and t h e p ro d u c t d i s t i l l e d a t low p r e s s u r e s .

T h is p ro c e d u re h as t h e a d v a n ta g e o f a v o id in g

o v e rh e a tin g w h ich r e s u l t s when magnesium s a l t s a r e p r e s e n t d u r in g th e d i s t i l l a t i o n . B ecause o f i t s low v o l a t i l i t y , a m o d ifie d p ro c e d u re was u se d f o r TNB.

I n t h i s c a s e t h e s o l u t i o n was c o n c e n tr a te d and p oured

in to a c r y s ta lliz in g d is h .

"When c r y s t a l l i z a t i o n was c o m p le te , t h e

p ro d u c t was f i l t e r e d and r e c o v e re d .

R e c r y s t a l l i z a t i o n was th e n

c a r r i e d o u t i n t h e ab sen ce o f a i r . A ll th e t r i a r y l b o r o n s a r e s o l i d .

The m e ltin g p o i n t s ran g e

from 136° f o r t h e p h en y l d e r i v a t i v e t o 203° f o r th e a lp h a - n a p h th y l d e r iv a tiv e .

W ith t h e e x c e p tio n o f TNB, th e t r i a r y l b o r o n s a r e

r a t h e r s e n s i t i v e to t h e oxygen o f a i r . in c r e a s e d i n s o l u t i o n .

S e n s i t i v i t y t o o x id a tio n i s

The members o f t h i s s e r i e s a p p e a r t o b e

s tr o n g e r a c id s th a n th o s e o f t h e a lk y l s e r i e s .

The compounds show

a marked te n d e n c y t o combine w ith n itr o g e n b a s e s .

The fo rm a tio n o f

a l k a l i m e ta l a d d itio n compounds i s an u n u su al phenomenon shown t y th e a r y l - b u t n o t t h e a lk y lb o r o n s . The a d d i t i o n p ro d u c ts w ith n itro g e n o u s b a s e s a r e made by p a s s in g t h e g aseo u s b a s e in to o r adding th e l i q u i d b a s e t o an e th e r

5

s o lu t i o n o f th e a r y lb o ro n i n an atm o sp h ere o f n i t r o g e n .

W ith a few

e x c e p tio n s , th e s e a d d itio n compounds a re f a i r l y in s o lu b le i n e t h e r and c r y s t a l l i z e o u t w ith l i t t l e d i f f i c u l t y .

S in c e m ost of t h e

compounds a re s t a b l e t o a i r , t h e s o l i d s can th e n b e f i l t e r e d and h an d led i n a i r . The a d d itio n compounds w ith n itro g e n o u s b a s e s a r e w h ite s o l i d s , s t a b l e t o a i r , i n c o n t r a s t w ith t h e a d d i tio n compounds o f t h e a lk y lb o ro n s . T rib e n z y lb o ro n e x h i b i t s in te r m e d ia te p r o p e r t i e s i n b e in g slo w ly o x id iz e d i n a i r .

As a group th e s e compounds a r e g e n e r a ll y s o lu b le

i n b e n z e n e , o f low s o l u b i l i t y i n g a s o lin e o r p e tro le u m e t h e r , and o f v a r i a b l e s o l u b i l i t y i n a lc o h o l. b a s e s c o n ta in

A ll a d d itio n compounds w ith n itro g e n o u s

one mole o f b a s e p e r mole o f a r y lb o ro n ( lU ) .

a d d itio n compounds o f TUB a r e e x c e p tio n a l.

Two

These c o n ta in t h r e e m oles

o f p y r id in e and two m oles o f p i p e r id i n e p e r mole of b o ro n compound. The t r i a r y l - a s w e ll a s t h e t r ia lk y lb o r o n s do n o t f o r a a d d it io n compounds w ith e t h e r . When e th e r s o lu tio n s o f t h e a ry lb o ro n s a r e t r e a t e d w ith sodium w ire , o r o th e r a l k a l i m e ta ls , h ig h ly c o lo re d a d d itio n compounds, w hich a r e r a t h e r i n s o l u b l e i n e t h e r , a r e o b ta in e d .

T rib e n z y lb o r on e x h i b i ts

th e same b e h a v io r i n c o n t r a s t t o th e a lk y lb o ro n s which do n o t r e a c t w ith t h e s e m e ta ls .

These compounds a re an alo g o u s t o trip h e n y lm e th y l i n

t h a t th e y a re e x tre m e ly s e n s i t i v e t o a i r and m o is tu re . A lth o u g h TNB, l i k e a l l o th e r a r y lb o ro n s , form s an a d d itio n compound c o n ta in in g one mole o f sodium p e r mole of th e a r y lb o ro n , i t a ls o form s a s t a b l e d i s odium a d d itio n com plex.

B en t and Dorfman (U)

made co n d u ctan ce m easurem ents on sodium trip h e n y lb o r o n and d i s odium

6

TNB i n d i e t h y l e th e r s o l u t i o n .

They e x p la in t h e i r d a ta i n te rm s o f

t h e f o llo w in g e q u ilib riu m c o n s ta n ts : K = ( N a + X r .) (NaR)

and

K' = (NagR*)

w here R i s tr ip h e n y lb o r o n and R1 i s THE.

Thus, a lth o u g h b o th s a l t s

a r e w eakly d i s s o c i a t e d , th e TNB canpound shows t h e rem ark ab le p r o p e r ty o f g iv in g tw o sodium io n s a t t h e same tim e .

The a u th o rs i n t e r p r e t

th e s e r e s u l t s a s f a v o r in g a s t r u c t u r e i n w hich b o th sodium s a r e a tta c h e d a t a c a rb o n atom o f a n a p h th a q u in o id sy ste m o v er a s t r u c t u r e su ch as /~ ( a l pha -

“ Na*.

Sodium trip h e n y lb o r o n shows th e p e c u l i a r i t y o f b e in g c o l o r l e s s when a b o u t 70 p e r c e n t o f th e sodium has b een removed by m ercu iy .

B ent

and Dorfman ( 3 ) e x p la in t h i s b y t h e fo rm a tio n o f t h e f o llo w in g com plex w hich, th e y s a y , can e x i s t i n re s o n a n c e fo rm s; :N a:

tC ^H r^B :Na: *B( 0 ^ ) ^ .

Comparison o f t h e O b s e rv a tio n s o f Brown and S u j i s h i w ith Those o f K rause and Nobbe An i n v e s t i g a t i o n was c a r r i e d o u t b y Brown and S u j i s h i (5 ) i n o rd e r to t e s t t h e b a s e s tr e n g th o f th e amine s e r i e s , NH^, CH^NH^, (CH^^NH and (CH^)^N, w ith t h e r e f e r e n c e a c id TNB.

The p r o p e r t i e s

w hich th e y o b serv ed f o r TNB and i t s amine a d d iti o n compounds were

7

u n e x p e cted i n t h e l i g h t o f th e work done b y K rause and Nobbe ( 1 6 ) . The d i f f e r e n c e s i n t h e o b s e rv a tio n s o f th e s e i n v e s t i g a t o r s a r e a s f o llo w s : O b s e rv a tio n s o f K rause and Nobbe

O b se rv a tio n s o f Brown and S u j i s h i 1.

TNB c o n ta in s one m ole o f b e n zen e o f c r y s t a l l i z a t i o n .

1.

TNB c o n ta in s two m oles o f ben zen e o f c r y s t a l l i z a t i o n .

2.

TNB i s e x tre m e ly s t a b l e i n a ir.

2.

TNB shows a p p r e c ia b le o x i­ d a t io n i n a i r a f t e r a fo rtn ig h t.

3.

TNB i s s l i g h t l y s o lu b l e i n e t h e r . 3 .

TNB i s m o d e ra te ly s o lu b le i n e th e r.

U.

The TNB a d d itio n compound w ith U. ammonia p r e c i p i t a t e s v e iy slo w ly from e t h e r s o lu t i o n upon m ixing th e com ponents.

The TNB a d d it io n compound w ith ammonia p r e c i p i t a t e d im m ed iately upon m ixing th e com ponents.

5.

A d d itio n compound o f TNB w ith trim e th y la m in e co u ld n o t be p r e p a re d .

A d d itio n compound w ith trim e th y la m in e was i s o l a t e d .

6.

A d d itio n compounds w ith ammonia 6 . and m ethylam ine showed f u g i t i v e m e ltin g p o i n t s a t 17 0 -2 °a n d 15>0-5° re s p e c tiv e ly .

No m ention i s made of f u g i t i v e m e ltin g p o i n t s .

?•

F re s h ly p re p a re d a d d i t i o n coopounds of TNB w ith ammonia, m ethylam ine, and dim etb y lam ine gave h ig h e r p r e s s u r e s th a n o ld e r sam ples o r t h o s e h e a te d t o a h ig h te m p e r a tu re .

No work was r e p o r te d on r e a c t i o n s betw een s o l i d TNB and th e gaseous am in es.

5*

?•

Brown and S u j i s h i s tu d ie d t h e b e h a v io r of th e ammonia and amine a d d itio n compounds i n a h ig h vacuum l i n e .

I t was o b serv ed t h a t

th e p r e s s u r e o v er th e f r e s h l y p r e p a re d ammonia a d d i tio n compound v a r ie d w it h th e m ole f r a c t i o n o f ammonia.

P re s s u re m easurem ents w ere

made on t h e f r e s h l y p re p a re d a d d i tio n compound c o n ta in in g a m olar

8

r a t i o o f t h e com ponents.

A p l o t o f lo g P v s . —- showed ex p ected

l i n e a r i t y a t low te m p e r a tu r e s .

However, a t h ig h e r te m p e ra tu re s t h e

cu rv e showed a d e v i a t i o n fro m l i n e a r i t y due to low p r e s s u r e s . te m p e ra tu re s above 120°

At

t h e p r e s s u r e d e c lin e d n o tic e a b ly w ith tim e .

The r a t e o f d e c re a s e was a t f i r s t v ery r a p id a t lU 0 °, b u t th e n d im in ish e d .

A c o n s ta n t p r e s s u r e was f i n a l l y re a c h e d a f t e r tw e n ty

h o u rs . T his p ro d u c t gave a new s e r i e s o f p r e s s u r e s a t e l e v a te d te m p e ra tu re s .

The p l o t of lo g P v s . -J— was now l i n e a r and q u ite

r e p r o d u c ib le .

In c o n t r a s t t o t h e f r e s h l y p re p a re d compound t h e

d i s s o c i a t i o n p r e s s u r e s o f t h i s m a te r ia l w ere in d ep en d en t o f c o m p o sitio n . T h at th e o b s e rv a tio n s w ere n o t due t o an i r r e v e r s i b l e change * i n th e TNB was shown t y t h e f a c t t h a t t h e p ro d u c t o b ta in e d b y rem oval o f th e ammonia a t h ig h te m p e r a tu r e s , re a b s o rb e d th e amine a t low te m p e ra tu re s t o undergo t h e same b e h a v io r . Brown and S u j i s h i advanced th e h y p o th e s is o f r o t a t i o n isom erism i n TNB and i t s a d d i t i o n compounds in o r d e r to e x p la in t h e above d is c r e p a n c ie s .

T h is iso m erism i s t h e r e s u l t o f r e s t r i c t e d r o t a t i o n

o f th e a lp h a - n a p h th y l g ro u p s.

A p e r s p e c tiv e o f th e two isom ers

t h a t a r i s e from r e s t r i c t e d r o t a t i o n i s shown i n F ig u re 1 , w h ile p la n a r r e p r e s e n t a t i o n s a r e g iv en below .

Sym m etrical Unsymme t r i c a l

10

The unsym m etrica l iso m er m i l b e more h in d e re d d u e t o th e b lo c k in g o f t h e boron atom by t h e p e r i p o s it i o n of r i n g U .

The

p r o je c t io n o f th e p e r i p o s i t i o n i n t o th e r e g io n o ccu p ied by th e amine m o lecu le w i l l r e n d e r th e a d d i tio n compounds o f t h i s isom er l e s s s ta b le . A ll t h e o b s e rv a tio n s a r e e a s i l y e x p la in e d i f Brown and S u jis h i i s o l a t e d t h e u n sy m m etrical is o m e r, w h ile K rause and Nobbe i s o l a t e d t h e sy m m etrical fo rm .

T hus, Brown and S u j i s h i d id n o t i s o l a t e th e

trim e th y la m in e a d d itio n compound presum ably b e c a u se o f th e la r g e h in d ra n c e a ffo rd e d by t h e p e r i p o s it i o n i n t h e un sy m m etrical is o m e r. The u n u s u a l b e h a v io r o f t h e d i s s o c i a t i o n p r e s s u r e o f th e o th e r amine a d d itio n compounds i s a c c o u n te d f o r i f a t r a n s i t i o n from th e unsymme t r i c a l t o t h e s ta b l e sy m m e tric a l isom er ta k e s p la c e . I n t h i s r e s e a r c h TNB and i t s a d d itio n compounds w ere examined from t h e v ie w p o in ts o f t h e i r b e h a v io r i n s o lu t i o n and i n t h e s o l i d s ta te .

The w ork i s p r e s e n te d i n fo u r c h a p te r s .

F i r s t , th e p r e p a r a tio n

o f th e compounds u sed i n t h e r e s e a r c h ; t h i s i s g iv e n i n C hapter I I . Second, t h e b e h a v io r o f th e compounds i n t h e s o l i d s t a t e ; t h i s i s g iv e n i n C h ap ter I I I .

T h ird , t h e b e h a v io r o f TNB upon c r y s t a l l i z a t i o n

from v a r io u s s o lv e n ts and t h e s o l u b i l i t i e s o f TNB; t h i s i s g iv e n i n C hapter IV .

F i n a l l y , t h e b e h a v io r of th e s u b s ta n c e s i n s o lu tio n i s

co v ered i n C h ap ter V.

11

CHAPTER I I THE PREPARATION OF VARIOUS FORMS OF TRI-ALPHA-NAPHTHTLBORON AND ITS BENZENE SOLVATE D is c u s s io n The P r e p a r a tio n o f TNB b y t h e Method o f Bro-wn and S u j i s b i (5)> I n t h i s p ro c e d u re benzene was u s e d to s o l u t i z e th e G rig n ard r e a g e n t, a lp h a -naphtbgrlmagnesium b ro m id e, w hich p r e c i p i t a t e d ft*cm s o lu tio n * Boron t r i f l u o r i d e - e t h e r a t e i n a benzene s o l u t i o n was th e n added t o t h e G rig n ard re a g e n t, and th e r e s u l t i n g p ro d u c t was h y d ro ly z e d by ad d in g th e s o lu t i o n to i c e and c o n c e n tr a te d h y d ro c h lo ric a c id i n a fla s k .

The f l a s k w i t h t h e p ro d u c t was l e f t i n a r e f r i g e r a t o r o v e r n ig h t.

The s o l i d m a t e r i a l , w hich c o n s is te d o f th e p ro d u c t and in o rg a n ic s a l t s , was f i l t e r e d and c r y s t a l l i z e d from r e f l u x in g b en zen e.

The h o t

benzene s o lu t i o n was f i l t e r e d and when c o o l p la c e d i n a r e f r i g e r a t o r o v ern ig h t*

The s o lid re c o v e re d from t h i s s o lu t i o n was h e a te d t o a tem ­

p e r a t u r e o f l5 0 - l6 0 ° a t l e s s th a n one m illim e te r p r e s s u r e t o remove th e b en zen e o f c r y s t a l l i z a t i o n .

The p ro d u c t o b ta in e d i n t h i s manner

w i l l b e r e f e r r e d t o a s h e a t - t r e a t e d TNB. I n t h e p r e s e n t w ork t h e same p ro c e d u re was fo llo w e d e x c e p t f o r t h e h y d r o ly s is o f t h e in o r g a n ic s a l t s * t o add th e r e a c t i o n m ix tu re a c id i n a s e p a r a to r y f u n n e l.

I t was found

more c o n v e n ie n t

to t h e i c e and c o n c e n tra te d h y d ro c h lo ric The lo w er l a y e r , c o n ta in in g th e in o rg a n ic

s a l t s , co u ld th e n b e s e p a r a te d , and th e u p p e r l a y e r , f r e e o f in o r g a n ic m a t e r i a l s , c o u ld b e added t o a f l a s k w hich was p la c e d i n a r e f r i g e r a t o r .

12

I t was much e a s i e r t o f i l t e r th e r e s u l t i n g p r o d u c t.

T h is was f r e e

o f g e la tin o u s in o rg a n ic s a l t s and was much e a s i e r t o c r y s t a l l i z e from b e n z e n e . The P r e p a r a tio n o f TNB by th e Method of K rause and Nobbe ( 1 6 ). These w o rk ers made o n e - h a lf of th e G rig n ard r e a g e n t i n t h e u s u a l manner o f ad d in g t h e h a lid e i n e t h e r s o lu t i o n t o t h e magnésium*

The

r e a c t i o n was th e n c o n tin u e d b y t h e a d d itio n o f an e th e r s o lu tio n c o n ta in in g b o ro n t r i f l u o r i d e and th e h a l i d e . known a s t h e B a rb ie r r e a c t i o n .

(T h is p ro c e d u re i s

The a u th o r s s t a t e t h a t th e p r e p a r a tio n

can a ls o b e c a r r i e d o u t b y f i r s t p r e p a r in g th e G rig n ard r e a g e n t. ) The c l e a r s o lu t i o n was t r e a t e d w ith w a te r w hich h y d ra te d th e magnesium s a lts .

The e t h e r s o lu t i o n was th e n p o u red o f f from th e h y d ra te d

magnesium s a l t s w hich s tu c k t o t h e w a lls o f t h e f l a s k .

T h is s o lu t io n

was th e n c o n c e n tra te d and p o u red i n t o a c r y s t a l l i z i n g d is h w here c r y s t a l l i z a t i o n to o k p la c e a t o n ce. I n t h e p r e s e n t p r e p a r a ti o n e s s e n t i a l l y th e same p ro c e d u re was fo llo w e d .

The G rig n a rd r e a g e n t was p r e p a re d f i r s t and th e boron

t r i f l u o r i d e - e th e r a t e i n e th e r s o lu t i o n was th e n ad d ed .

However, th e

f i n a l p ro d u c t p r e c i p i t a t e d o ut o f s o lu t io n g iv in g a t h i c k mass w hich was v e ry d i f f i c u l t to h a n d le .

T h is mass c o u ld n o t b e e a s i l y removed

from t h e f l a s k ; on t h e o t h e r hand, t h e a d d itio n o f w a te r t o th e f l a s k gave r i s e to a m ix tu re o f TNB and in o r g a n ic s a l t s .

I n an a tte m p t

t o keep t h e f i n a l p ro d u c t i n s o lu tio n , t h e q u a n t i t i e s of r e a g e n ts was red u c ed b y o n e - h a lf u s in g t h e same amount o f e th e r as b e fo re j s t i l l .

13

t h e f i n a l p ro d u c t d i d n o t s ta y i n s o lu t i o n .

Only when th e amount

o f r e a g e n ts was re d u c e d t o o n e - fo u r th u s in g th e same amount o f e th e r was a c l e a r s o l u t i o n o b ta in e d . Two p r e p a r a tio n s w ere c a r r i e d o u t u s in g o n e - fo u r th o f t h e o r ig in a l q u a n titie s o f re a g e n ts .

I n t h e f i r s t p r e p a r a tio n t h e

o r i g i n a l 500 m l. of e t h e r s o l u t i o n , o b ta in e d a f t e r h y d r o ly s is , was e v a p o ra te d b y a s p i r a t i o n t o o n e - h a lf o f i t s o r i g i n a l volum e. l i t t l e p r e c i p i t a t e o f s o l i d was o b ta in e d .

Very

Upon e v a p o ra tio n t o

o n e - fo u r th o f t h e o r i g i n a l volume about 13 g . o f TNB was o b ta in e d . I n t h e second p r e p a r a t i o n , th e o r i g i n a l 500 m l. o f s o lu ti o n , re d u ce d t o 250 m l., gave ab o ut 12 g . o f TNB.

When t h i s volume was

red u ced to ab o u t 120 m l ., an a d d i t i o n a l 1 .7 g. o f TNB was o b ta in e d . Thus, f o r t h e f i r s t cro p o f p ro d u c t th e r e w ere ab o u t 5 grams o f TNB p e r 100

m l. of s o l u t i o n , b u t f o r th e second crop o f p ro d u c t t h ç r e

w ere o n ly ab o u t 1 .3 g . o f TNB p e r 100 m l. o f s o l u t i o n .

The la r g e

a p p a re n t s o l u b i l i t y o f t h e f i r s t cro p was p ro b a b ly due t o s u p e rs a tu ra tio n .

Thus, t h e l a r g e s o l u b i l i t y r e p o r t e d t y K rause and Nobbe

was p ro b a b ly b a s e d on t h e s o l u b i l i t y i n a su p e r s a tu r a te d s o lu t i o n . P u r i f i c a t i o n o f TNB O btained fro m t h e E th e r S o lu tio n .

K rause

and Nobbe p u r i f i e d TNB u s in g th e th r e e - b u lb a p p a ra tu s d e s c rib e d b y K rause and P o lack ( 1 8 ) .

To o b ta in

a p r o d u c t as s i m i l a r t o K rause and

Nobbe1s as p o s s i b l e , t h i s a p p a ra tu s was u sed to p u r if y some o f th e TNB from t h e l a s t p r e p a r a t i o n .

lU

The P r e p a r a tio n o f THB-benzene from H e a t- tr e a te d TNB. T h is p r e p a r a tio n was c a r r ie d o u t when a s tu d y o f th e n a tu r e o f t h i s compound w as u n d e rta k e n .

Two p r e p a r a tio n s w ere made t y r e c r y s t a l l i z i n g

h e a t - t r e a t e d TNB from b e n z e n e .

When th e compounds w ere h e a te d

under vacuum 1 .0 6 m oles o f b en zen e i n one c a s e and 1 .0 7 m oles in th e o th e r (T ab le 1 ) were l i b e r a t e d f o r e a c h mole o f TNB.

The s l i g h t

ex cess o f benzene was fo u n d t o b e th e r u l e and i s p ro b a b ly due to a s o lu t i o n o f b e n zen e i n s o l i d TNB-benzene.

T hat t h i s i s t h e c a se i s

su p p o rte d b y d i s s o c i a t i o n p r e s s u r e m easurem ents o f TNB-benzene ( C hapter III).

The p r e s s u r e o f t h e compound a s p re p a re d was 38 mm. b u t rem ains

c o n s ta n t a t ab o u t 26 mm. a f t e r t h e i n i t i a l e x c e s s o f b en zen e i s removed *

E x p e rim e n ta l D e t a i l s The same a p p a ra tu s was used f o r e v e ry p r e p a r a tio n o f TNB. T h is c o n s is te d o f a s ta n d a rd 1 - l i t e r 3 -n eck ed f l a s k , f i t t e d b y s ta n d a r d - ta p e r g la s s j o i n t s t o a c o n d e n se r, m e rc u ry -se a le d s t i r r e r , and a d ro p p in g f u n n e l w ith a n itr o g e n i n l e t .

The f l a s k c o n ta in in g

th e magnesium was d r i e d b y warming w ith a f r e e flam e w h ile th e a p p a ra tu s w as sw ept o u t w ith n itr o g e n . The a lp h a - b r om onaphthal ene and th e boron t r i f l u o r i d e - e t h e r a t e (b o th Eastman-Kodak Company C hem icals) u sed i n th e fo llo w in g e x p e ri­ m ents w ere vacuum d i s t i l l e d .

The b o i l i n g p o in ts were l l f l to 1U3°

a t 11; mm., an d 78° a t 8It ram., r e s p e c t i v e l y .

15

The P r e p a r a tio n o f TNB by t h e Method o f Browi and S u j i s h l . To 2U«3 g» o f magnesium t u r n i n g s was added a s o lu t i o n o f 10 m l, of a lp h a -brom onaphthalene and 0 .3 m l. o f m eth y l io d id e i n 100 m l. o f e th e r.

The r e a c t i o n was s t a r t e d by h e a tin g on t h e steam b a th and

was c o n tin u e d b y t h e a d d itio n o f a s o lu tio n o f 130 m l. o f th e brom ide (making a t o t a l o f 1 m ole) i n U00 m l. o f e t h e r . r e q u ir e d 3*25 h o u rs .

The a d d itio n

No p r e c i p i t a t e form ed d u rin g th e a d d i tio n ,

n e v e r th e le s s , 100 m l. o f b en zen e was added a t t h e c o m p le tio n o f t h e a d d itio n .

The s o lu t i o n was th e n r e f lu x e d f o r one h o u r.

The s o l u t i o n was c o o le d w ith i c e , th e i c e b a th rem oved, and a s o lu t i o n o f 32 m l. (0 .2 5 m ole) o f b o ro n t r i f l u o r id e - e th e r a t e i n 150 m l. o f benzene was added i n one h o u r.

The r e a c t i o n m ix tu re was

r e f lu x e d f o r one hour and was th e n f o rc e d o v e r th ro u g h a g la s s tu b e , b y means o f n itr o g e n p r e s s u r e , i n t o a 2-1* E hrlenm eyer f la s k o n e -h a lf f u l l o f i c e and c o n ta in in g 50 m l. of c o n c e n tr a te d h y d ro c h lo ric a c id . The s o lu tio n a f t e r th e e t h e r a t e a d d i t i o n was deep r e d , b u t a f t e r h y d r o ly s is t h e s o l u t i o n was y e llo w .

The f l a s k was s to p p e re d and l e f t

o v e rn ig h t i n a r e f r i g e r a t o r a t a b o u t 10° C. The m ix tu re was f i l t e r e d u s in g a Buchner fu n n e l (w ith o u t f i l t e r p ap er).

Some s o lid r a n th ro u g h th e f u n n e l .

T his was p ro b a b ly

cau sed b y c h a n n e lin g i n i t i a t e d b y t h e g e la tin o u s m a te r ia l.

An

a c c id e n t a t t h i s p o i n t r e s u l t e d i n th e l o s s o f some m a t e r ia l. s o l i d was washed w ith w a te r and th e n w ith 95 p e r c e n t e th a n o l. cru d e s o l i d w eighed 90 g .

The The

16

The p ro d u c t was d is s o lv e d i n 300 m l. of b o i l i n g ben zen e u n d er a n itr o g e n atm osphere and p oured th ro u g h a prewarmed Buchner fu n n e l (w ith f i l t e r p a p e r ) in to a 1 - 1 . E hrlenm eyer f l a s k .

The f l a s k was

s to p p e re d and p la c e d i n a r e f r i g e r a t o r o v e rn ig h t. The s u p e rn a ta n t l i q u i d was poured o f f and th e s o l i d w ashed w ith c o ld b e n ze n e.

The s o lid was t r a n s f e r r e d t o th e f u n n e l and

f i n a l l y p la c e d i n a w eighed 300-m l. round -b o tto m ed f l a s k . was e v a c u a te d t o remove a d h e rin g s o lv e n t. TUB.

was

The f l a s k

W eight o f th e s o l i d ,

g . (39 p e r c e n t o f t h e t h e o r e t i c a l b ased on boron

trif lu o rid e - e th e r a te ).

The b e n z e n e o f c r y s t a l l i z a t i o n was removed

by h e a tin g t o c o n s ta n t w eig h t a t 155° a t l e s s th a n one m illim e te r p re ssu re .

The r e s u l t i n g p ro d u c t w eighed 3 7 .2 g . , a l o s s o f 8 .1 g .

compared w ith 7*5 g . o f benzene c a lc u la te d f o r th e 1 to 1 compound. The compound m elte d a t 2 0 5 .2 t o 2 0 6 .2 ° ( c o r r . ) . The P r e p a r a tio n o f TNB b y t h e M odified Method o f Brown and S u jis h i.

A c r y s t a l o f io d in e was added to 2U.3 g. (1 g* atom ) of

magnesium i n t h e f l a s k .

The f la s k was h e a te d u n t i l th e io d in e had

sublim ed and allo w ed t o c o o l t o room te m p e r a tu re .

A s o lu t i o n o f

10 m l. o f a lp h a - b ro m onaphthalene i n 100 m l. of e t h e r was added, and th e r e a c t i o n was s t a r t e d by h e a tin g on th e steam b a th .

Meanwhile

130 m l. o f a lp h a -brom onaphthal ene (m aking a t o t a l o f 1 m ole) was d is s o lv e d i n an a d d i t i o n a l U00 m l. o f anhydrous e th e r .

T his s o lu tio n

was th e n slo w ly added th ro u g h th e d ro p p in g f u n n e l a t such a r a t e as t o keep t h e e th e r g e n tly r e f l u x i n g .

Toward t h e m iddle of t h e a d d itio n

an a p p r e c ia b le amount o f t h e G rig n ard r e a g e n t had s e p a r a te d .

B enzene,

17

100 m l., was added t o d i s s o l v e th e G rig n ard r e a g e n t and th e a d d it io n o f t h e e t h e r - h a l i d e s o lu t i o n c o n tin u e d . r e q u ir e d t o add th e h a l i d e .

A t o t a l o f th r e e hours was

The r e a c t i o n m ix tu re was th e n r e f lu x e d

f o r one h o u r. The f l a s k was n e x t c o o led i n i c e , t h e ic e ^ b a th rem oved, and a s o l u t i o n o f 32 m l. (0 .2 $ m ole) o f b o ro n t r i f l u o r i d e - e t h e r a t e i n 1$0 m l. o f b enzene was added t o th e G rignard re a g e n t o v e r a p e rio d o f $0 m in u te s .

The r e a c t i o n m ix tu re was th e n h e a te d u n d er r e f l u x f o r

one and one—h a l f h o u rs .

The r e a c t i o n m ix tu re was f o rc e d u n d er n itr o g e n

p r e s s u r e th ro u g h a g la s s tu b e i n to a 2 - l i t e r s e p a ra to r y f u n n e l about o n e - th ir d f u l l o f i c e and c o n ta in in g $0 m l. o f c o n c e n tra te d h y d ro c h lo ric a c id .

The lo w e r in o r g a n ic la y e r was th e n s e p a r a te d and t h e u p p er

y e llo w l a y e r washed once w ith 150 m l. of c o ld w a te r and tw ic e w ith 100 m l. of co ld w a te r . fla s k .

The y e llo w la y e r was th e n p la c e d in a 1 - l i t e r

The f l a s k was s to p p e re d an d l e f t o v e rn ig h t i n a r e f r i g e r a t o r

f o r t h e c r y s t a l l i z a t i o n o f t h e TNB. The n e x t day t h e s u p e r n a ta n t l i q u i d was d e c a n te d th ro u g h a B uchner f u n n e l from th e y e llo w s o l i d .

The s o l i d was th en washed w ith

two $0 m l. p o r tio n s and two 30 m l. p o r tio n s of 95% e th a n o l.

The s o l i d

was t r a n s f e r r e d t o t h e B uchner f u n n e l d u r in g t h e l a s t two w ash in g s. The s o l i d had changed from a golden y e llo w t o a l i g h t y e llo w i n c o lo r . The c ru d e p ro d u c t w eighed 82 g .

T his was d is s o lv e d i n 300 m l. o f

r e f lu x in g b en zen e ( n itr o g e n atm o sp h ere) and q u ic k ly p o u red th ro u g h a prewarmed B uchner f u n n e l in to a $00 m l. Ehrlenm eyer f l a s k . th e f l a s k was d is p la c e d b y n i tr o g e n , t h e f l a s k w as s to p p e re d p la c e d i n a r e f r i g e r a t o r o v e r n ig h t.

The a i r i n and

18

The n e x t day t h e s u p e r n a ta n t l i q u i d was p oured o f f and th e s o l i d b ro k en up w ith a s t i r r i n g r o d .

The c r y s t a l s w ere washed w ith

two 25 m l. p o r tio n s o f c o ld b e n z e n e and th e n t r a n s f e r r e d t o a w eighed f l a s k and t h e a d h e rin g s o lv e n t rem oved b y v o l a t i l i z a t i o n u n d e r h ig h vacuum to c o n s ta n t w e ig h t.

T h is p ro d u c t, T N B .% % , w e i^ ie d 5U-3 g . ,

a y i e l d o f 1&6.5# b ased on t h e b o ro n t r i f l u o r i d e - e th e r a t e u s e d . m e ltin g p o in t o f t h i s s u b s ta n c e was ta k e n .

A

Most o f th e s o li d m e lte d

a t 185 t o 187° and t h e l a s t t r a c e m elted a t 192° . The benzene of c r y s t a l l i z a t i o n was removed b y h e a tin g t h e f l a s k and i t s c o n te n ts t o a te m p e ra tu re o f l5 0 - l6 0 ° a t p r e s s u r e s of l e s s th a n one m i l l i m e t e r .

A f te r t h e f l a s k had re a c h e d c o n s ta n t

w e ig h t, t h e p ro d u c t w eighed Ult.3 g .

The p ro d u c t l o s t 1 0 .0 g . compared

w ith 9 .0 g . o f b enzene c a lc u la te d f o r t h e 1 to 1 compound.

The

compound m e lted a t 203 t o 205° ( c o r r .) . A sample o f 1.2U70 g . o f th e p ro d u c t was d is s o lv e d i n 75 m l. o f b en zen e and t i t r a t e d w ith 0 . 1261* norm al sodium metho:x±de i n m ethanol u s in g p h e n o lp h th a le in a s i n d i c a t o r 5 25.1*0 m l. o f b a s e w ere r e q u ir e d .

A b la n k p re p a re d from 75 m l. o f b e n z e n e and 25 m l. of

m eth an o l r e q u ir e d O.ll* m l. o f b a s e .

T hus, 3.179 m illim o le s (121*7.0/

3 9 2 .3 ) o f TNB r e q u ir e d 3 .1 9 3 m illim o le s (2 5 .2 6 x 0.1261*) o f b a s e . T h is i s a 0.1* p e r c e n t e x c e ss of b a s e . A sam ple o f t h e compound was s u b m itte d f o r m ic r o - a n a ly s is . C a lc u la te d f o r

C, 9 1 .85 H, 5.1*0. Found5

C, 92 .O5 H, 5.1*1*.

19

The P r e p a r a tio n o f TNB by th e P ro c e d u re o f K rause and Nobbe. To 2 lu 3 g* o f magnesium tu r n in g s was added a s o lu tio n o f 10 m l. o f a lp h a -brom onaphthal ene and 0 .2 m l. of m eth y l io d id e i n 90 m l. o f e t h e r . The r e a c t i o n was s t a r t e d b y h e a tin g on th e stea m b a th and was c o n tin u e d by t h e a d d itio n o f a s o l u t i o n o f 130 m l. o f a lp h a - brom onaphthal ene i n 250 m l. o f e t h e r .

The a d d iti o n was com pleted i n one hour and

t e n m in u tes a f t e r w hich t h e r e a c t i o n m ix tu re was r e f lu x e d f o r IS m in u te s . A s o lu tio n o f 32 m l. (0 .2 5 m ole) o f b o ro n t r i f l u o r i d e - e t h e r a t e i n 125 m l. o f e th e r was added t o th e warm G rig n ard r e a g e n t.

A f te r

ab o u t t h r e e - f o u r t h s o f t h e s o lu t io n was added, a p r e c i p i t a t e had form ed.

Upon co m p letin g t h e a d d i tio n , th e r e a c t i o n m ix tu re was h e a te d

u nder r e f l u x f o r 1 .2 5 h o u rs .

The p r e c i p i t a t e was g e l a t i n o u s .

t h i s m ix tu re was added 108 m l. o f w a te r .

To

The a d d itio n o f th e f i r s t

1*0 m l. r e s u l t e d i n a v ig o ro u s r e a c t i o n , c o o lin g b y an i c e b a th b e in g r e q u ir e d .

The r e a c t i o n was much l e s s v ig o ro u s f o r t h e rem ain d er o f

th e a d d itio n .

D u rin g t h e w a te r a d d itio n t h e c o lo r changed from r e d

t o l i g h t y e llo w .

The s o l i d r e s id u e was gumny.

A ll a tta c h m e n ts w ere d isc o n n e c te d from th e r e a c t i o n f l a s k . The s o l i d was t r a n s f e r r e d a s r a p i d l y a s p o s s i b l e t o a fu n n e l w ith a s in te re d g la s s d is k .

About tw o - th ir d s o f th e s o lid was on t h e f u n n e l.

T h is was im m ed iately w ashed w ith two 25 m l. p o r tio n s o f e th e r and t r a n s f e r r e d t o a 300 m l. ro u n d -b o tto m ed f l a s k . th e s o l i d made t h e t r a n s f e r d i f f i c u l t .

The gumny n a tu r e o f

The f l a s k was th e n e v a cu ated

to l e s s th a n one m illim e te r p r e s s u r e t o remove a d h e rin g s o lv e n t . Meanwhile th e s o li d re m a in in g i n th e r e a c t i o n f l a s k was t r a n s f e r r e d

20

t o t h e f u n n e l and w ashed w i t h e t h e r . s o lid .

T h is was added t o th e o th e r

A bout 70 g . o f c ru d e p ro d u c t was c b ta in e d .

Magnesium s a l t s

could b e p l a i n l y d is c e rn e d i n th e TNB. A sam ple o f 1 ,2 9 8 g. of t h i s p ro d u c t r e q u ir e d 2 5 ,5 m l. o f 0.126U norm al sodium m eth o x id e.

However, th e y e llo w c o lo r o f th e

benzene s o lu t i o n made i t d i f f i c u l t t o ju d g e th e end p o i n t .

A sam ple

o f p u re TNB would have r e q u ir e d 2 6 .2 m l ., hence th e r e was 97 p e r c e n t TNB.

T h is v a lu e i s u n q u e s tio n a b ly h ig h b e c a u s e o f t h e o b scu red end

p o in t. The P r e p a r a tio n o f TNB by a M o d ified P ro ced u re o f K rause and Nobbe U sing a L a rg e r P r o p o rtio n o f E th e r .

The r e a c t i o n was s t a r t e d

by adding 5 m l. o f a lp h a - brom onaphthalene and 0 .1 m l. of m eth y l io d id e i n 50 m l. o f e th e r t o 6 .1 0 g . (0 .2 5 g . atom ) o f magnesium tu r n in g s and h e a tin g on t h e ste a m c o n e .

The r e a c t i o n was c o n tin u e d b y a d d in g a

s o lu t i o n o f 30 m l. o f h a lid e ( a t o t a l o f 0 .2 5 m o les) i n 300 m l. o f e th e r i n U5 m in u te s.

The r e a c t i o n m ix tu re was s t i r r e d f o r f i f t e e n

m in u tes and th e n r e f lu x e d f o r f i f t e e n m in u te s .

A s o lu tio n o f 8 m l.

( o n e - s ix te e n th m o les) o f b o ro n t r i f l u o r i d e - e t h e r a t e i n 250 m l. of e th e r was th e n added t o t h e h o t s o lu tio n i n 35 m in u te s .

Two la y e r s

w ere p r e s e n t , an u p p e r c l e a r re d d ish -b ro w n l a y e r and a lo w er deep re d la y e r .

The m ix tu re w as th e n r e f lu x e d f o r tw e n ty m in u te s.

B o ile d d i s t i l l e d w a te r , 37 m l. (2 m o le s), was added to th e m ix tu re w i t h slow s t i r r i n g . cone d u rin g t h e a d d i t i o n .

The m ix tu re was k e p t warm on t h e steam A t t h e end o f th e a d d iti o n t h e r e was a

su sp e n s io n o f f i n e p a r t i c l e s i n t h e e t h e r s o lu t i o n .

The ta c k y

21

h y d ra te d magnesium s a l t s w ere p r e s e n t a t t h e b o tto m o f th e f l a s k . The h o t e t h e r s o l u t i o n was p oured o f f from t h e s a l t s th ro u g h a warmed 3*25 in c h c o u rse s i n t e r e d g la s s f u n n e l. i n t h e e t h e r w ent th ro u g h th e f u n n e l.

The f i n e p a r t i c l e s suspended The e th e r s o lu t i o n (a b o u t 500 m l.)

was th e n ev a p o ra te d t o ab o u t h a l f o f t h e o r i g i n a l volume and p la c e d i n a r e f r i g e r a t o r o v e r n ig h t. th e f l a s k .

T here was v e r y l i t t l e s o l i d p r e s e n t i n

F i l t r a t i o n o f th e s o lu t io n gave 0 .5 g . o f p ro d u c t w hich

had a l a r g e amount o f in o r g a n ic s a l t s .

The f i l t r a t e was e v a p o ra te d

on t h e a s p i r a t o r to h a l f o f i t s p r e s e n t volume and p la c e d i n a re frig e ra to r. The s o lu tio n was f i l t e r e d th e n e x t day and th e s o li d was sucked a s d ry as p o s s i b l e . f o r f u tu r e u s e .

The f i l t r a t e was s to r e d i n a r e f r i g e r a t o r

The s o l i d was p la c e d i n an 8 - in c h t e s t tu b e ,a n d t h e

tu b e was e v acu ated on t h e w a te r a s p i r a t o r t o c o n s ta n t w e ig h t. l i g h t y e llo w s o li d w eighed 1 2 .2 g .

The

Some s o l i d re m a in in g i n th e f l a s k

was washed once w ith e th e r and f i l t e r e d .

T h is w h ite s o l i d w eighed

0 .6 g . ( y i e l d b ase d on 1 2 .8 g . was 52 p e r c e n t o f th e t h e o r e t i c a l ) . Two m e ltin g p o in ts w ere ta k e n o f t h e y e llo w s o l i d .

The m e ltin g

p o in t i n an e v ac u ate d tu b e was 156 to 1 8 5 °; w h ile i n a tu b e f i l l e d w ith n i tr o g e n t h e m e ltin g p o in t was llUi t o 1 5 5 °.

The m e ltin g p o in t

o f th e w h ite s o l i d was 195 t o 199° i n an e v a c u a te d tu b e . A second p r e p a r a tio n was c a r r i e d o u t by t h i s m ethod.

T h is

tim e a somewhat l a r g e r amount of G rig n ard r e a g e n t was p re p a re d t o b e s u re t h a t a l l o f t h e b o ro n t r i f l u o r i d e was c o n v e rte d t o tiie p r o d u c t. To 7#3 g* (0 .3 0 g . atom ) o f magnesium was added a t o t a l o f U2 m l. o f a lp h a -b ro m onaphthalene (0 .3 0 m o les) i n a t o t a l of 350 m l. o f e th e r

22

d u r in g 1 .$ h o u r s .

The m ix tu re was r e f lu x e d f o r one h o u r.

D u rin g th e

r e f l u x i n g a p r e c i p i t a t e form ed w hich c le a r e d d u rin g t h e a d d it io n of 8 m l. ( o n e - s ix te e n th m o les) o f b o ro n t r i f l u o r i d e - e t h e r a t e i n 150 m l, o f e th e r.

T h is a d d itio n to o k 0 .7 5 h o u rs and was fo llo w e d by 0 .3 3

h o u rs o f r e f l u x i n g .

Then 36 m l. o f b o ile d d i s t i l l e d w a te r was added

and t h e e th e r s o lu t i o n was f i l t e r e d and e v a p o ra te d on th e a s p i r a t o r from ab o u t 500 t o 250 m l.

The r e s u l t i n g s o lu t i o n was p la c e d i n a

r e f r i g e r a t o r o v e r n ig h t. The s o lu tio n was f i l t e r e d t h e n e x t d ay and t h e s o l i d when ev acu ated t o c o n s ta n t w e ig h t

was 1 1 .8 g.

The f i l t r a t e was e v a p o ra te d

t o ab o u t 120 m l. and l e f t i n a r e f r i g e r a t o r o v e r n ig h t.

T h is s o lu tio n

gave 1 .7 g* and i n th e p ro c e s s o f f i l t r a t i o n an a d d it i o n a l 0 .3 g . came o u t i n t h e f i l t r a t e .

A t o t a l o f 1 3 .8 g . (52 p e r c e n t of th e

t h e o r e t i c a l ) was o b ta in e d .

A sam ple o f t h e f i r s t f r a c t i o n m elted a t

197 to 199° i n an e v ac u ated tu b e . The P u r i f i c a t i o n o f TNB Using th e T h re e -b u lb A pparatus of K rause and P o lack ( 1 8 ) .

The a p p a ra tu s u sed i n t h e p r e s e n t experim ent

was made from b u lb s o f t h r e e 5O~ml. round-bottom ed f l a s k s . draw ing o f t h e a p p a ra tu s i s g iv en i n F ig u re 2 .

A

The necks o f th e f l a s k ,

w hich w ere a p p ro x im a te ly 120° a p a r t , jo in e d a t t h e apex

form ing th e

s u r f a c e o f a h em isp h ere. TUB, I t.2 g . , o b ta in e d i n t h e l a s t p r e p a r a tio n was p la c e d i n b u lb C th ro u g h tu b e c and t h e tu b e c was s e a le d .

The a p p a ra tu s was

ev acu a te d th ro u g h tu b e a on t h e h ig h vacuum l i n e and 35 m l. o f e th e r was a d m itte d th ro u g h tu b e a and condensed on th e TNB i n b u lb C.

2k

The e t h e r had b ee n p r e v io u s ly pumped f r e e o f a i r i n th e h ig h vacuum l i n e , d r i e d over calciu m h y d rid e i n th e l i n e and a g a in pumped f r e e of g ases.

Tube a was th e n s e a le d o f f f r a n t h e l i n e and th e a p p a ra tu s

was re a d y f o r use» The t h r e e b u lb s o f t h e a p p a ra tu s w ere p la c e d i n a b a th a t ab o u t l45°»

A fiter about tw en ty m in u tes th e e t h e r s o lu tio n i n C was

d e c a n te d i n t o A b y t i l t i n g t h e a p p a r a tu s .

The e th e r i n A was th e n

d i s t i l l e d b a c k t o C b y p la c in g b u lb s A and B i n warm w a te r and C i n c o ld w a te r .

The s o l i d i n A had a y e llo w is h c o lo r .

I t was t h e r e f o r e

d ecid e d t o c o n tin u e d e c a n tin g s o lu ti o n s in t o B and t o u s e A a s t h e s to r a g e f o r im pure TUB.

W ith t h e e th e r a g a in in C, a l l th e

b u lb s w ere p la c e d i n t h e b a th a t ab o u t ii5 °.

T his tim e th e e th e r

s o lu tio n was d e c a n te d i n t o B and t h e e th e r d i s t i l l e d b ack t o C. T h is d e c a n tin g an d d i s t i l l i n g was re p e a te d u n t i l b u lb B had m ost o f t h e TUB and f i n a l l y th e e th e r .

Bulb B was th e n cooled t o about

- 5 ° , th e r e s t o f th e a p p a ra tu s was c o o le d t o z e ro d e g r e e s , and th e c o ld e th e r s o lu t i o n was d e c a n te d i n t o A.

The a p p a r a tu s was th e n

co n n ected to t h e h ig h vacuum l i n e b y s e a lin g tu b e b i n t h e tu b e b re a k e r.

The t i p o f b was b ro k e n and t h e e th e r was d i s t i l l e d o u t

from t h e t h r e e b u lb a p p a r a tu s .

The a p p a ra tu s was pumped out o v e r n ig h t,

b u lb B was c u t o f f and 3 .1 g . o f w h ite s o l i d was re c o v e re d . I t may p ro v e u s e f u l i n f u tu r e work t o p la c e a s in t e r e d g la s s d is k i n t h e neck o f f l a s k C.

T h is would p re v e n t s o li d from coming

o ver w ith t h e d e c a n te d s o l u t i o n , and b u lb C c o u ld f i n a l l y b e u sed f o r th e s to r a g e o f i m p u r i t i e s .

25

The P r e p a r a tio n o f TNB-benzene.

T his compound was p re p a re d

by r e c i y s t a H i z i n g h e a t - t r e a t e d TNB from b en zen e t h a t was d r ie d o v er calciu m h y d r id e .

Two p r e p a r a tio n s w ere c a r r i e d o u t .

I n each c a se

th e TNB was d is s o lv e d i n b en zen e under r e f l u x i n a n it r o g e n atm osphere and f i l t e r e d .

The s o l u t i o n was l e f t i n a r e f r i g e r a t o r f o r one day,

th e s o l i d was f i l t e r e d , washed w ith c o ld b e n zen e, and sucked d r y u s in g a ru b b e r dam.

The ground s o l i d was th e n ev acu a te d a t room

te m p e ra tu re t o remove a d h e rin g s o lv e n t .

I n t h e f i r s t p r e p a r a tio n 27g.

of TNB was d is s o lv e d i n 250 m l. o f benzene and 1 9 .U g . o f p ro d u c t was i s o l a t e d .

I n th e sec o n d p r e p a r a tio n 17 g . o f TNB was d is s o lv e d

i n 75 m l. o f b en zen e and 15+9 g . o f p ro d u c t was i s o l a t e d . The m olar r a t i o o f TNB t o benzene was th e n d e te rm in e d .

The

TNB was f r e e d o f b en zen e by h e a ti n g to c o n s ta n t w e ig h t a t 150 t o l6 0 ° under vacuum.

T h is r e q u ir e d t h r e e to f o u r h o u rs.

T a b le 2

g iv e s t h e r e s u l t s . T a b le 2 R a tio o f Benzene to TNB i n TNB-Benzene P re p a r­ a tio n No.

Wt. o f TNB-%%

W t. o f R esidue (TNB)

E xpected w t. f o r 1 :1 r a t i o

Moles Moles TNB

1

5 .0 9 9

U.192

lu 253

1 .0 7

2

2 .258

1 .8 6 0

1 .8 8 3

1 .0 6

26

CHAPTER I I I THE BEHAVIOR OF TRI-ALPHA-NAPHTHTLBORON AND ITS ADDITION COMPOUNDS IN THE SOLID STATE O b se rv a tio n s and D is c u s s io n D is s o c ia tio n P r e s s u re M easurem ents o f TNB-ammonia. O b se rv a tio n o f a Minimum i n th e P re s su re-C o m p o sitio n Curve.

The A sample

o f s t a b l e TNB-ammonia was s y n th e s iz e d i n th e vacuum l i n e from h e a t t r e a t e d TNB, and th e d i s s o c i a t i o n p r e s s u r e s were d ete rm in e d a t th e te m p e ra tu re s r e p o r te d by Brown and S u j i s h i ( 5 ) .

D i f f i c u l t y was

e x p e rie n c e d n o t o n ly i n re p ro d u c in g t h e i r r e s u l t s , b u t a ls o i n g e ttin g c o n s is te n t r e s u l t s .

The p r e s s u r e a t a g iv e n te m p e ra tu re was found

t o depend on w h eth er t h e te m p e ra tu re was approached from above or belo w .

F iv e d i f f e r e n t sam ples o f TNB-ammonia showed th e same b e h a v io r.

The r e s u l t s f o r a t y p i c a l ru n a r e g iv e n i n T able 3 , and a summary o f th e p r e s s u re r e a d in g s o b ta in e d f o r th e f i v e sam ples i s given i n T ab le li.

The l a t t e r shows th e v a r i e t y o f p r e s s u r e s o b ta in e d a t any

one te m p e r a tu re .

From t h i s t a b l e i t a p p e a rs t h a t a d e c re a s e i n

p r e s s u r e fo llo w s a d e c r e a s e i n t h e amount o f ammonia. The dependence o f t h e p r e s s u r e on th e d i r e c t io n fro m w hich th e te is p e r a tu r e was ap p ro ach ed i n d i c a t e s a slow ap p ro a c h t o e q u ilib r iu m . The o n ly way t h i s slo w n ess can b e overcome i s by a llo w in g s u f f i c i e n t tim e f o r e q u ilib riu m to b e e s ta b lis h e d . The p o s s ib le dependence of t h e d i s s o c i a t i o n p r e s s u r e on th e co m p o sitio n p o in te d t o a s o l i d s o lu t i o n phenomenon.

The n e x t ex p erim en t

»

27

T able 3 D is s o c ia tio n P r e s s u r e s o f TNB-Ammon i a W eight o f TUB Amount o f NH3 u sed Amount o f NHo r e q u ir e d Mole % NH3 Time

Temp.

P r e s s , i n mm.

liq .a ir d ry i c e 2 5 .1 1*0 .1 138 11*0

0 .7 25 32 .7 310 176

Second day 1 0:00 1 0 :U i 10:58 1 1 :33 11:1*7 12:12 1:00 2:08 2 : 1*0 i*:03 1*:19 1*:1*3 5:22 8:1*5

11*0 .0 1 5 0.2 1 5 9 .9 1 6 0 .2 1 7 0 .0 1 7 0 .0 1 6 0 .0 1 6 0 .0 1 5 0 .0 1 5 0 .0 11*0 .1 11*0 .2 1 3 0 .0 51*

0.3155 U6.0 1*6.6 9 8 .6 Time

Temp.

P re ss. :

T h ird day

F i r s t day 1:58 2:10 3 :0 5 3:3 5 5 :00

= = = *»

1 2 .6 2 0 .1 3 1 .8 3 3 .5 5 7 .7 6 0 .6 1*0 . 1* 37.2 2 3 .1 2 3 .0 1 5 .3 11*.8 9 .5 2 .9

2 .1 25 .6 1 m l. o f NHo removed. Mole % NH-i = 97.1*. 1 1 :1 5 IO9 .7 .9 1 1 0 .0 1 .0 11:25 11:36 2 .0 1 1 9 .9 1 2 0 .0 11:53 2 .3 1:5 0 1 3 0 .0 1*.5 1 3 0 .1 2:17 lw5 11*0 .0 2:1*3 9 .5 11*0 .0 2 :53 9.1* 1 5 0 .0 3:13 1 6 .7 1 5 0 .0 3 :1 5 17 .3 11*0 .0 3:U0 9 .6 3:52 160.2 3 1 .1 1 6 0 .0 It: 13 31.1* 1*:25 11*9.9 1 9 .1 1*:36 1 8 .1 1 5 0 .0 11*0 .0 10 i*:51* 10 5 :0 2 11*0 .0 32 . 1* 5:2 5 1 6 0 .3 1 6 0 .0 3 2 .1 5 :3 5 5 :5 0 3 5 0 .1 1 8 .5 1 50.0 5 :5 5 1 8 .5 11*0 .0 6:12 1 0 .5 6 : 21* 11*0 .0 1 0 .3 F o u rth day 9 :1 8

11*0.0

9 .6

28

T able U Summary o f D is s o c ia tio n P re s s u re s f o r F iv e Sam ples o f TNB-ajimionla

ample

Mole %

Temp. 110°

120°

130°

1U00

i5o°

160°

170°

9 .5

1 2 .6

2 0 .1

33.5 3 7 .2

6 0 ,6

3

9 8 .6

5

9 8 ,6

3

9 7 .U

1 .0

2 .3

U.5

9.U 1 0 .3

1 7 .3 1 8 .5

31.U 3 2 .1

2

96 .5

1 .5

3 .0

6 .3

1 2 .2

22 .u

3 9 .1 U0.5

k

9 5 .6

0 .8

2 .3

8 .1 1 0 .8

1

9U.2

1 0 .3

5

9 3 .9

8 .6 8 .9

2

8 8 .0

1 2 .6 11 .7

2 9 .6 18

3 6 .8

1 5 .7

3 0 .1 31.7

5

1 6 .2

2 s

30.7 30 .7

5.U

1 9 .5

30.U

7 3 .3

29

was d e s ig n e d , t h e r e f o r e , to t e s t f o r t h i s phenomenon.

In th is

e x p erim e n t t h e change o f d i s s o c i a t i o n p r e s s u r e w ith th e amount of anm onia was o b serv ed a t lU 0o «

A m olar ex cess o f ammonia was added

to TNB and th e sam ple k e p t a t lUO° f o r tw e n ty - fiv e h o u rs . was t h e n rem oved p o rtio n w is e an d th e p r e s s u r e s r e c o rd e d .

Ammonia The

r e s u l t s f o r t h i s r u n a r e g iv en u n d e r Run 1 i n T a b le 5 . I f TNB form ed a s o l i d s o lu tio n i n TNB-ammonia, t h e d i s s o c i a t i o n p r e s s u r e sh o u ld d e c r e a s e from 100 t o some v a lu e b elo w 100 mole p e r c e n t ammonia i n t h e re g io n o f u n s a tu r a te d s o i u t i on, and l e v e l o f f t o a c o n s ta n t v a lu e w here a s a tu r a te d s o lu tio n e x i s t e d . i s shown i n F ig u re 3 . n o t c o n c lu s iv e .

T h is b e h a v io r

The r e s u l t s p o i n t t o t h i s b e h a v io r b u t a r e

R e f e r r in g t o T a b le 9 , t h e p r e s s u r e a t 9 9 .6 p e r c e n t

anmonia was 9 .3 mm., t h a t a t 9 7 .5 p e r c e n t, o b ta in e d on th e f o u r th day a f t e r e le v e n h o u r s , was ab o u t 8 .9 mm., w h ile p r e s s u r e s betw een th e s e re a d in g s w ere low er i n d i c a t i n g a la c k o f e q u ilib r iu m .

The

d i f f e r e n c e i n th e s e tw o v a lu e s , however, may o r m^r n o t b e s i g n i f i c a n t f o r i t i s w ith in th e e r r o r of th e method ( ab o u t 0 .3 mm.).

A la c k

o f c o n c lu s iv e n e s s a p p a r e n tly a r i s e s a ls o from th e sm all change i n p r e s s u r e and t h e s m a ll r e g io n w here an un s a tu r a te d s o lu t io n may e x i s t . An a tte m p t was n e x t made to d e f in e t h e re g io n where t h e r e was a n u n s a tu r a te d s o lu t i o n o f TNB i n TNB-ammonia by rem oving sm all p o r ti o n s o f g a s i n t h e r e g io n around 100 mole p e r c e n t ammonia.

The

ammonia removed fro m t h e TNB i n Run 1 was r e tu r n e d and a g a in l e f t i n c o n ta c t w ith t h e TNB.

Removal o f ammonia was s t a r t e d a f t e r th e

sam ple was h e a te d a t lU 0° f o r a b o u t t e n h o u rs . q u i t e u n ex p ected (Run 2 , T a b le 5 ) .

The r e s u l t s w ere

A lthough sm all amounts o f ammonia

Table $ V a r ia tio n o f D is s o c ia tio n P r e s s u re o f TNB-ammonia a t llj.0o •with. Change i n Mole P er C ent of. Ammonia W eight o f TNB Amount of NHo u sed Amount o f NH3 r e q u ir e d Mole % NH3

= = « =

.8535 5 l . l m l. 1*8.8 10U.8

P a r t Ül - T a b u la tio n o f P re s s u re R eadings Time

Mole % NH,

P ress. .(nm.)

Run 1 F i r s t day 10U.8 11:19 II 11:20 M 1:09 If 8:03

liq .a ir rm. tem p. 110* 77

Second day 9 :3 6 10U.8 « 2 : 10. M 7 :50 It 8:25 8 ilt0 10Ù.3 It 8 :55 1 0 3 .2 9 :0 5 n 9:2 2 9 :3 0 1 0 2 .3 n 9:1:6 1 0 0 .8 9 :5 3 » 10118 1 0:30 9 9 .6

70 6 8 .0 6 7 .2 6 6 .8 6 1 .1 6 0 .9 1*7.2 1*7.1 3 6 .6 3 6 .5 1 9 .1 1 9 .2 9 .3

T h ird day 10 :15 11:20 12:08 1 2:20 1:58 2 :0 9 3 :01 3:17 U:01 U:35 9:1:0

9 .2 8 .0 8 . 1* 7 .6 8 .3 8 .0 8 .2 8 .0 8 .2 1 2 .8 9 .2

9 9 .6 9 8 .8 11

9 8 .1 11

9 7 .0 n 9 5 .7 ;< / 9 7 .5 «

Time

Mole % NHi

P re s s (mn.

F o u rth day 8 :5 5 97.5 it *9 :3 0 11 10:20 M #10:22 II 10:52

8 .9 9 .6 8 .8 8 .2 8 .5

Run 2 101*. 8 it 11 11 « 103.1 11 1 00.9 11

81 7 1 .8 67.1* 6 6 .6 6 6 .0 1*5.7 1*5 .8 1 9 .5 1 9 .5

F i f t h day 100.9 10:25 100. 1* 1 0:35 n 11:05 11:20 100.0 it 11:30 11:37 99.7 11 1 1 :5 5 12 :0 3 9 9 .3 11 2:07 2 :16 9 8 .6 H 2:30 97 .5 2:31* 11 2 :58 11 3 :2 5 it 3:1*0

1 9 .2 11*. 2 l l i .5 1 0 . 1* 1 0 .I* 8 .5 8.7 6 .8 6 .9 5 .2 5 .3 lt.0 7 .6 8 .2 8 .2

11:13 11:55 1:2 5 5 :5 0 8:56 9:06 9:26 9:35 9:1*5

L e v el o f m ercury i n manometer was in c r e a s e d . L e v el o f m ercury i n manometer was d e c re a s e d .

31

T a b le 5 c o n tin u e d Time

Mole % . Mh

P re ss, (mm. )

F i f t h day ( c o n t, ) 9U.8 3*51 n U*07 n U:17 » U*17 U*58 9 0 .3

7.1i 8.U 8 .3 8 .5 7 .7

S ix th day 11:58 9 0 .3 it 11:59 1 2 :5 0 Sl^.O ii 1 :0 0 tt 1 :1 0 7U.0 5 :5 1 « 6:07

8 .5 8 .5 8 .5 8 .5 8 .7 8 .3 8 .5

Time

Mole % mx _

P re ss, (ram. )

S ev en th day 8:U0 7U.0 It 8:1:3 3.1:10 6 3 .5 it 1 1 :3 0 3 :3 8 5 1 .1 n 7:32 3 8 .2 9:17

8.5 8 .6 8.1: 8 .6 8 .1 8 .6 8 .0

E i ^ i t h day 9:3 0 3 8 .2

8 .3

P a r t B - Summary o f P r e s s u re R eadings Run 1 Mole % NHt 10L. 8 10U.3 1 0 3.2 1 0 2 .3 1 0 0 .8 9 9 .6 9 8 .8 9 8 .1 9 7 .0 95.7 9 7 .5

Run 2 P re ss. (ram. ) 6 6 .8 6 0 .9 U 7.1 36 .5 1 9 .2 9 .2 8.1: 8 .3 8 .2 8 .2 8 .9 o r 8 .6

Mole % NHn 101:. 8 1 0 3 .1 100.9 1 0 0 .U 1 0 0 .0 99.7 9 8 .6 9 7 .5 91:. 8 9 0 .3 8U.0 7U.0 6 3 .5 5 l.l 3 8 .2

P re ss. (ram. ) 6 6 ,0 1:5.8 19.2 1U.5 i o .U 8.7 5 .3 U.o to 8 .5 8 .5 8.7 8.7 8*6 8*6 8 .3

33

w ere removed i n th e r e g io n below 100 mole p e r c e n t, th e p r e s s u r e d e c r e a s e s were q u i t e m arked.

F u rth e rm o re , th e p r e s s u r e c o n tin u e d

t o d ro p w ith each rem oval of ammonia show ing no in c r e a s e w ith tim e . F or exam ple, s h o r t l y a f t e r ammonia was removed g iv in g 9 9 .3 mole p e r c e n t o f ammonia, th e p r e s s u r e

was 6 .8

mm. ( 1 2 :0 3 ) , w h ile two h o u rs

l a t e r (2 :0 7 ) t h e p r e s s u r e was

6 .9 mm.

Only a f t e r 9 7 .5 p e r c e n t ammonia

was re a c h e d d id a sh a rp p r e s s u r e r i s e o c c u r. ammonia t o g iv e 9 7 .5 p e r c e n t

T hus, a f t e r rem oval o f

th e p r e s s u r e was U.Omm. (2 :3 1 0 , b u t

i n 19 m in u tes ( 2 :U3) th e p r e s s u r e (3$U0) th e p r e s s u r e was 8 .2 mm.

was

5 .8 mm., and i n ab o u t one hour

H e r e a f te r th e p r e s s u r e rem ained

e s s e n t i a l l y c o n s ta n t upon f u r t h e r rem oval of ammonia.

The r e s u l t s

f o r t h i s ru n a r e shown i n F ig u re U. The r e p r o d u c i b i l i t y o f t h i s phenomenon was checked u s in g a new sam ple o f TNB-ammonia.

An ex cess o f ammonia was l e f t i n

c o n ta c t w ith TNB a t 1U0° f o r a b o u t 85 h o u rs .

The ammonia was th e n

removed p o rtio n w is e and t h e p r e s s u r e s r e c o r d e d . g iv en i n T ab le 6 and shown i n F ig u re 5 .

The r e s u l t s a r e

The p r e s s u r e a g a in showed

th e b e h a v io r o f re a c h in g a minimum v a lu e .

The p r e s s u r e i n t h i s c a s e

showed a minimum a t ab o u t 9 7 .U p e r c e n t ammonia.

T h is i s i n agreem ent

w ith th e v a lu e o b ta in e d i n Run 2 , T able 5 . One more sam ple o f THB-ammonia was p r e p a re d .

T h is was done

t o b e s u re t h a t t h e phenomenon was r e p r o d u c ib le and to check th e p o s i t i o n o f th e minimum p o i n t .

A gain an e x c e ss o f ammonia was l e f t

i n c o n ta c t w ith THE a t lli0 ° f o r ab o u t 85 h o u rs .

The d a ta i n T able 7

g iv e t h e r e s u l t s when ammonia was removed p o r tio n w is e . p l o t t e d i n F ig u re 6 .

This d a ta i s

The e f f e c t i s a g a in o b se rv e d , b u t th e minimum

swaiawmiw

ni

aynsssya

35

T ab le 6 V a r ia tio n o f D is s o c ia tio n P r e s s u re o f TMB-anaaonia m tfa Change i n Mole P er Cent o f Ammonia a t Üb.QO W eight o f TNB Amount o f NH^ u sed Amount o f Nik r e q u ir e d H ole % NH3

= = = =

0.881; 5 2 .7 m l. 5 0 .5 m l. 10U.3

P a r t A - T a b u la tio n o f P r e s s u re R eadings Time

Mole % NH^

F i r s t day 2:00 10l;.3 7:20 «

P r e s s , (mm.) 390 98

Second day U:U0 10U.3 k '.té "

78 7 5 .2

T h ird day 9 :3 0 10U.3 3:00 »

7 0 .8 7 0 .0

F o u rth day 10:30 10W 2:30 «

6 6 .6 6 6 .8

F i f t h day 9 :0 0 10U.3 9 :3 5 " 10:18 « 10:35 1 0 1 .6 1 0 :5 k 1 0 0 .6 11:32 1 0 0 .U 11 : 111 1 0 0 .0 1:32 « 1:1*3 9 9 .5 2 :15 9 9 .5 2:27 9 9 .0 3 :0 5 9 9 .0 3 :1 0 9 8 .5

6 5 .8 6 6 .2 6 6 .2 2 7 .2 l k .5 ll.U 7 .8 8 .2 6 .1 6.1* 5 .9 6 .0 5 .1

Time 3 :5 1 3 :5 6 U:37 U:l*l 5 :1 9 5 : 21* 6 : 01* 8:02 8:25 9:20

Mole % NHn 9 8 .5 9 8 .0 tl 97.U « 9 6 .8 11 « 9 6 .k 11

S ix th day 9:20 9 6 .k 1 0:05 9 9 .9 tt 9:1 5

P r e s s , (im 5 .3 k .9 5 .2 k .7 5 .7 5 .0 6 . 1* 7 .9 6 . 1* 7 .6 8 .0 3 7 .3 23 .5

S ev en th day 1 8 . 1* 9 :3 0 9 9 .9 « 1*:00 1 0 .3 Lowered Hg i n manometer frcm 18 1 .2 to 5 8 .3 o r ab o u t 6 m l. v o l . change 1*:01 8 .9 9 9 .9 n 5 :0 0 9 .3 8 .6 5 :0 5 9 8 .9 E ig h th day 8:35 9 8 .9 11 1 :3 0 9 8 .6 1 :3 6 11 9 :2 0

8.1* 8.1* 5 .7 8 .1

36

T a b le 6 co ntinued* P a r t B - Summary o f P r e s s u re R eadings Mole % NH3

P re ss. (mm.)

Mole % nh3

P re ss , (mm.)

10U.3 101.6 100.6 100 .U 100.0

66.2 27.2 1U.5 n .U

9 7 .U 96.8

5.7

9 9 .5 99*0 9 8 .5 9 8 .0

6.U 6.0

98.6

8.1

7 .9 8.0 96 . u 1 0 .3 99 .9 W ith Hg lo w ered 9 9 .9 9 .3 8.U 98.9

8.2

5 .3 5 .2

T ab le 7 V a r ia tio n o f D is s o c ia tio n P re s s u re o f TNB-aramonia •with Change i n Mole P e r Cent o f Ammonia a t ll|O.Ou W eight o f TNB Amount o f NHo u sed Amount o f NHo r e q u ir e d Hole % NH3 P a r t A — T a b u la tio n o f P re s s u re Time

Mole % NH3

F i r s t day ItiUO 10U.3

P re ss, (mm. )

A b t. h30

Second d^y 10s00(«n)10U .3 8 :3 0 "

92.7 85 .3

T h ird day 9 :1 0 lO lt.3 5 :1 0 «

8 2 .3 8 1 .1

F o u rth day 9 :0 5 10U.3 5 :0 0 "

7 8 .8 7 9 .3

= • = =

0.810- g . 5 0 .1 U8.0 10U.3

R eadings Time

Mole % NH3

F i f t h day 9 :0 0 10U.3 I* 9 :5 0 10:01 103.5 II 10:13 10:20 1 03.0 II 1 0:32 10:36 1 0 2 .1 « 10:1*9 10:56 100.1* It 11:21* 11:31 9 9 .7 ii 11:50 12 :0 0 9 9 .1

P re ss , (mm.)

7 7 .7 7 8 .1 6 6 .3 66 S 5 9 .1 5 9 .1 3 9 .1 3 9 .2 1 9 .9 20 .2 1 2 .7 1 2 .8 9 .2

37

T a b le 7 c o n tin u e d Time 1 :0 5 1 :2 1 1:1*0 1 :2 1 2 :1 1 2 :1 5 2:35 2:37 2:56 3 :0 0 3 :2 0 3:25 3:1*6 3:1*9 1*:11

Mole % nh3 9 9 .1 9 8 ,6 ii 9 7 .9 H 9 7 .2 h

9 6 .6 n 9 6 .0 M 9 5 .U n 9U.7 M

P re ss, (mm. ) 9 .1 7 .1 7 .3 6 .6 6 .6 5 .7 6 .0 5.1* 5 .9 1*.5 6 .6 5 .6 6 .7 5 .8 7 .1

Time 1*:15 i*:35 1*:1*1 5 :0 2 8:22 S ix th d ^ r 9 :3 6 9 :5 5 10 :2 8 10:1*8 11 :0 0 11:23 11:1*8 12:07 12:30

Mole % NHo

P re ss, (mm. )

9l*.0 « 9 3 .3 n «

5 .9 7 .1 6 .3 7.1* 8 .2

9 3 .3 9 1 .2 n n 88.1* n n 8 5 .1 n

7 .8 3 .9 7 .6 7 .8 6 .0 7 .8 7 .9 6 .1 7 .9

P a r t B - Summary o f P r e s s u re R eadings Mole % NH^ 10l*.3 1 0 3 .5 1 0 3 .0 1 0 2 .1 100.1*. 9 9 .7 9 9 .1 9 8 .6 9 7 .9 9 7 .2

P ress?. (mm. ) 7 8 .1 66.1* 5 9 .1 3 9 .2 1 9 .9 1 2 .8 9 .2 7 .3 6 .6 6 .0

Mole % NH3 9 6 .6 9 6 .0 95.1* 91*.7 91*.0 9 3 .3 91.2 88.1* 8 5 .1

P r e s s . (mm. ) 5 .9 1*.5 t o 6 .6 6 .7 7 .1 7 .1 7 .8 7 .8 7 .9 7 .9

38

i s se e n t o b e a t a b o u t 9 6 .6 m ole p e r c e n t ammonia*

Hoivever, i t

■will b e o b se rv e d t h a t th e p r e s s u r e re a d in g s a t 100 m ole p e r c e n t a r e d i f f e r e n t f o r each e x p e rim e n t.

T hus, f o r t h a t re c o rd e d i n

T ab le 5 t h e p r e s s u r e i s 10*U mm. a t 100 p e r c e n t, i n T a b le 6 th e p r e s s u r e i s 8 .2 mm. a t 100 p e r c e n t, and i n T ab le 7 th e p r e s s u r e i s 12*8 mm. a t 99*7 p e r c e n t .

S in c e th e p r e s s u r e a t 100 mole

p e r c e n t i s e x p e c te d t o b e t h e same f o r any c a s e , th e p e rc e n ta g e s may be i n e r r o r .

I f s o , t h i s f a c t o r can b e e lim in a te d by ta k in g

th e p r e s s u r e e q u a l t o a b o u t 10 ram* a t 100 m ole p e r c e n t and by u s in g p r e s s u r e d i f f e r e n c e s .

The minimum o c c u rs a f t e r a b o u t 2 .5

p e r c e n t (1 0 0 -9 7 .5 ) i n T ab le 5> ab o u t 2 .7 p e r c e n t ( 1 0 0 .1 -9 7 -U) i n T a b le 6 , and a b o u t 3,3 p e r c e n t (9 9 ♦ 3 -9 6 .0 ) i n T able 7*

The

minimum can b e ta k e n a s 97#1 - 0*U mole p e r c e n t o f ammonia and i s c o n s ta n t a s f a r a s c an b e a s c e r ta in e d from th e s e e x p e rim e n ta l re s u lts . The u n u su a l o c c u rre n c e o f th e minimum i n th e p r e s s u r e co m p o sitio n d iag ram can b e e x p la in e d b y r e c a l l i n g t h a t i n th e f i r s t ex p erim en t (Run 1 , T ab le 5 ) t h e TNB and ammonia w ere i n c o n ta c t f o r 25 h o u rs , w h ile i n su b seq u en t e x p e rim e n ts t h e c o n ta c t tim e was g r e a t e r .

Hence i n t h e l a t e r e x p erim en ts th e TNB was

p ro b a b ly c o n c e rte d e n t i r e l y to t h e s t a b l e a d d itio n compound ( o r p erh ap s t o th e s t a t e w here a s o lu t i o n o f TNB i n TNB-ammonia was p r e s e n t) *

I n t h e s e sam ples when TNB was l i b e r a t e d b y rem oval o f

airmonia n u c l e i f o r c r y s t a l l i z a t i o n w ere n o t p r e s e n t .

T hese a p p a r e n tly

form ed o n ly a f t e r a minimum c o n c e n tr a tio n o f TNB was p r e s e n t i n s o lu tio n .

T h is c o n c e n tr a tio n o c c u rre d when a b o u t 97 ♦! p e r c e n t

39

ammonia was p r e s e n t i n t h e a d d i t i o n compound ( a t lliO0 )*

On th e

o th e r hand n o t a l l of' th e TNB was c o n v e rte d t o t h e a d d i t i o n compound i n t h e f i r s t ex p e rim e n t when t h e tim e o f c o n ta c t was l e s s .

In t h i s

c a s e s u f f i c i e n t TNB was p r e s e n t to c a u s e th e c r y s t a l l i z a t i o n of t h e new ly l i b e r a t e d TNB th u s p r e v e n tin g th e l a r g e d e v ia t io n from e q u ilib r iu m . I f t h i s i n t e r p r e t a t i o n i s c o r r e c t i t f o llo w s t h a t t h e d i s s o c i a ­ t i o n p r e s s u r e s a t 100 m ole p e r c e n t and i n th e r e g io n o f u n s a tu r a te d s o l u t i o n c o u ld b e m ost e a s i l y o b ta in e d when a l l o f t h e TNB h a s been c o n v e rte d to th e a d d i t i o n compound*

A t e s t f o r t h i s c o n v e rsio n

would b e t h e o c c u rre n c e o f th e minimum.

The c o n c e n tr a tio n w here

s a tu r a t e d s o l u t i o n conraences co u ld b e d eterm in e d by e x tr a p o la tin g t h e d i s s o c i a t i o n p r e s s u r e s o b ta in e d a t lo w e r m ole p e r c e n ta g e s . The B eh av io r o f H e a t- tr e a te d TNB upon A d d itio n o f 50 Mole P er Cent Ammonia.

A s im p le method f o r d is t i n g u i s h i n g betw een th e

two s o li d form s o f TNB, sh o uld th e y be i s o l a b l e , was d e s i r a b l e . The a d d i t i o n o f 50 mole p e r c e n t anmonia seemed s u i t a b l e .

One

would e x p e c t t o g e t a d i f f e r e n c e i n p r e s s u r e upon a d d itio n o f ammonia t o th e two fo rm s.

The a d d itio n o f anmonia t o u n sy m m etrical

TNB ( h e a t - t r e a t e d ) sh o u ld g iv e r i s e t o an a p p r e c ia b le p r e s s u r e w h ile t h e a d d i t i o n t o sym m etrical TNB sh o u ld g iv e r i s e t o t h e lo w p r e s s u r e fo rm o f TNB w h ich tms a z e r o d i s s o c i a t i o n p r e s s u r e below 1 0 0 °.

I t was d e c id e d t o u se 50 mole p e r c e n t ammonia f o r t h i s would

show t h e p re s e n c e o f sy m m etrical TNB i n a m ix tu re o f t h e two fo rm s.

The te m p e ra tu re o f 80° was fo u n d t o g iv e an a p p r e c ia b le

Uo

p r e s s u r e o v er t h e h e a t - t r e a t e d TNB.

F u rth e rm o re 9 "the p r e s s u r e

upon a d d i t i o n o f HO and 60 mole p e r c e n t o f ammonia was a l s o d e te rm in e d t o p ro v id e a m eihod f o r d e te rm in in g t h e r a t i o o f th e tiro form s p r e s e n t .

T hus, a m ix tu re c o n ta in in g 20 m ole p e r c e n t o f t h e

Sym m etrical TN^ w hich w ould g iv e r i s e t o low p r e s s u r e TNB-ammonia, upon a d d itio n o f 50 m ole p e r c e n t o f ammonia sh o u ld b ehave a p p ro x im a te ly a s TNB t o w h ich 3 0 0 /8 mole p e r c e n t ammonia w as ad d ed . T a b le 8 g iv e s t h e r e s u l t s o b ta in e d u s in g 38, U9 and 60 m ole p e r c e n t ammonia.

T hese v a lu e s a r e p l o t t e d i n F ig u re ? •

I t i s se e n

t h a t t h e p r e s s u r e becomes a p p ro x im a te ly c o n s ta n t a f t e r ab o u t 180 m in u te s. The B e h a v io r o f TNB O b tain ed from th e K rause and Hobbe P ro ced u re upon A d d itio n o f Ammonia.

The cru d e TNB w hich had p r e c i ­

p i t a t e d o u t o f t h e r e a c t i o n m ix tu re o f th e f i r s t p r e p a r a tio n was t e s t e d w ith 5 0 m ole p e r c e n t o f anm onia.

The p r e s s u r e a f t e r th e

a d d itio n o f ammonia was h ig h and a c o n s id e ra b le amount o f l i q u i d had condensed on th e c o o l p o r tio n o f th e system .

When th e g a s e s w ere

removed and f r a c t i o n a t e d , seme e t h e r , a c o n s id e ra b le amount of w a te r (ab o u t 25 m ole p e r c e n t o f "the TNB) and no anmonia w ere i s o l a t e d . I t was n o t d e a r w h eth er t h e ammonia had r e a c te d w ith th e TNB o r , p o s s i b l y , th e magnesium s a l t s , and from, w here t h e w a te r had come. A sam ple o f cru d e TNB o b ta in e d i n th e f i r s t p r e p a r a tio n by th e m o d ifie d K rause and Nobbe p ro c e d u re was h e a te d i n th e vacuum lin e .

About 0 .1 2 m illim o le s o f gas w ere l i b e r a t e d p e r m illim o le of

Ui

T a b le 8 Change of P re s s u re w ith Time o f F r e s h ly P re p a re d TNB-ammonia Using H e a t- tr e a te d TNB 80«0° -

0*30°

W eight o f TNB = 0.853 3 8 .3 Mole % NH3 Time P ress* (m in. ) (mm. ) 1 2è 3i h 5 6 8 10 15 18 2U 29 39 52 60 8U 106 120 151 218 2k0 262

96 77 63 57 U9 U3.8 3 6 .u 3 1 .8 25.U 2 3 .0 2 0 .0 1 8 .1 1 6 .1 l l t .2 1 3 .5 1 2 .0 1 0 .7 1 0 .lt 9 .7 8 .5 8 .5 8 .1

lt9 .0 Mole % NH3 Time P re ss. (m in .) (mm.) 3 7 10 lit 18 25 32 U3 57 73 82 102 167 198 211 227 242

106 65 52 42 36 3 0 .1 2 6 .4 2 3 .0 2 0 .5 1 7 .9 1 7 .6 1 6 .3 1 3 .7 1 2 .8 1 2 .5 1 2 .2 1 2 .1

5 9 .8 Mole % NH Time P ress. (m in .) (m il.) 2 3 4 5 6 7 10 14 20 30 40 50 60 70 90 120 150 170 190

136 109 93 80.5 72.5 6 6 .5 5 5 .8 46*8 3 9 .9 3 3 .8 3 0 .7 2 7 .9 2 6 .2 2 5 .2 23.2 21.3 1 9 .9 1 9 .6 1 9 .1

U3

TUB p r e s e n t and o n ly a f r a c t i o n o f t h i s g as was w ater*

T h is c l e a r l y

i n d i c a t e s t h a t TUB was n o t th e so u rc e o f th e w a te r i n t h e e a r l i e r ex p erim en t w i t h ammonia* A sam ple o f t h i s same p ro d u c t was th e n t e s t e d w ith ammonia* B ecause t h e p ro d u c t c o n s is te d o f o n ly ab o u t 90 p e r c e n t TNB i t seemed a d v is a b le t o t r e a t i t w ith 100 mole p e r c e n t o f ammonia* When t h i s was done a b o u t 97 p e r c e n t o f t h e added ammonia was e a s i l y re c o v e re d in d i c a t i n g t h a t no sy m m e tric a l TNB was p re s e n t* A sam ple o f TNB o b ta in e d from th e p u r i f i c a t i o n i n th e t h r e e b u lb a p p a ra tu s was u se d f o r th e n e x t ex p erim en t w ith ammonia*

When

t r e a t e d w ith U8 mole p e r cen t ammonia, th e p r e s s u r e s w ere somewhat h ig h (T a b le 9 ) a t th e end u n d o u b ted ly due t o some e th e r t h a t was p r e s e n t i n t h e TNB*

The r e s u l t s t h u s show ap p ro x im a te ly th e same

b e h a v io r a s h e a t - t r e a t e d TNB* An A ttem pt to P re p a re Sym m etrical TNB i n t h e S o lid S ta te * An a tte m p t was made t o p r e p a re sym m etric s i TNB from th e low p r e s s u r e form o f TNB-ammonia.

Hydrogen c h lo r id e , 9 .1 m l., was condensed on

2*17 m illim o le s o f TNB-aamonia and t h e m ix tu re l e f t a t 5£>°.

The

i n i t i a l p r e s s u r e o f t h e hydrogen c h lo r id e o v er th e s o l i d was 1 6 9 .6 mm*, and a f t e r a b o u t 1*5 h o u rs t h e p r e s s u r e was 165*3 mm. was th e n k e p t a t 60° f o r ab o u t 1*5 h o u r s .

The m ix tu re

The p r e s s u r e a t t h e s t a r t

was 168*8 mm. and a t th e end o f t h i s p e r io d i t was 155.7 mm.

The

r a t e a t w hich t h e hydro gen c h lo r id e was consumed was to o sm all f o r t h i s p ro c e d u re t o b e p r a c t i c a b l e so i t was n o t p u rsu ed f u r t h e r .

hh

T able 9

Change o f P r e s s u re w ith Time o f F r e s h ly P re p a re d TIUB-anmonia U sing TUB from t h e K rause and Nobbe P r e p a r a tio n

Time (m in .) P re ss. (mm.)

Time (ra in .) P re ss. (ram.)

*

W eight o f TNB M l. o f HH3 added ML. o f NHo r e q u ir e d Mole % MH3 T em perature

= = = •

0.882 g . 2J4..3 50.U U8.2 81 1°

2

3

U

5

6

8

81

73

65

59

56

50

10

12

U5.5

U2.1

17

20

110

135

lUO

36.U

3lt.L

2 2 .6

2 2 .2

18»

A d ry i c e b a th was a t tu b e b . F ig u re 8

US

D is s o c ia tio n P r e s s u re M easurements on TNB-benzene.

The

d i s s o c i a t i o n p r e s s u r e m easurem ents on TNB-benzene w ere made to d e te rm in e t h e n a tu r e o f t h i s s o lid *

I f a s o lu t i o n o f b en zen e i n

TNB o r o f TNB-benzene an d TNB were p r e s e n t , t h e p r e s s u re o f th e system w ould d e c re a s e a s b en ze n e was rem oved.

On t h e o t h e r hand, i f th e r e

w ere a c r y s t a l l a t t i c e compound w ith l i t t l e o r no s o l u b i l i t y , th e p r e s s u r e usould rem ain c o n s ta n t a s b en zen e was rem oved. The d i s s o c i a t i o n p r e s s u r e s w ere o b serv ed by ap p ro ach in g th e e q u ilib riu m from berth d i r e c t i o n s .

The tw o p r e p a r a tio n s o f TNB-

benzene ( T able 2) w ere u sed i n t h e s e e x p e rim e n ts.

S in ce th e r e was

some d i f f e r e n c e i n t h e i r b e h a v io r th e r e s u l t s f o r each p r e p a r a tio n w i l l be p r e s e n te d when t h e d i f f e r e n c e s a r i s e .

The approach t o

e q u ilib riu m frcm th e fo rw a rd r e a c t i o n ( d is s o c ia ti o n ) was v e ry slow f o r b o th p r e p a ra tio n s *

T a b le s 10 and U , w h ich g iv e t h e d a ta f o r

two d i f f e r e n t te m p e ra tu re s u s in g P r e p a ra tio n No. 1 , show t h a t th e p r e s s u r e s w ere s t i l l in c r e a s i n g a f t e r 180 h o u r s .

Tîïhen about t e n

p e r c e n t o f t h e b enzene was removed th e p r e s s u re was s t i l l in c r e a s in g a f t e r 15>0 h o u rs (T ab le 1 2 ) . I n ap p ro ach in g t h e e q u ilib riu m frcm. th e r e v e r s e d i r e c t i o n a b o u t 50 p e r c e n t o f th e b en zen e was d r iv e n o f f a t 80° and th e n added back t o t h e s o l i d .

The benzene was r a p id ly ab so rb ed a t 25°•

T ab le 1 3 , f o r a sam ple o f P r e p a r a tio n N o ./2 , shows t h i s and a lso t h a t o n ly a f t e r ab o u t 30 days d o es th e system ap p ear t o have re a c h e d an e q u ilib riu m p r e s s u r e o f 3 8 .3 mm.

The d i f f e r e n c e i n t h e b e h a v io r o f

TNB-benzene o c c u rre d when a b o u t te n p e r c e n t o f th e benzene was

U6

Table 10 Dissociation Pressure of TNB-benzene» Preparation No, 1, at 2^,0° 0.1° P r e s s u r e (mm. )

Time ( h r s . )

10

io .5

1 7 .5 23 35 11 U8 60 72

P re s s u re (mm. )

.;

88 96 109 121 132 1 3 9 .5

0

0 11 15

Time ( h r s . )

11.2

1 2 .3 lU.U l 5 .l t 16.2 1 8 .3 2 0 .lt

22 1

23.lt 2U.0 2l;.0 2U.7 2 5 .0 2 5 .3 25.8 2 6 .0 26.8 2 7 .U

156

167 180 192 201;

T able 11 D is s o c ia tio n P r e s s u re of TNB-benzene, P r e p a r a tio n Ho» 1 , a t 3 9 .1 ± 0 .2 ° Time ( h r s . ) 0 1 2 .5 lit 18 22 33.5 1|2.5 60 72 83.5 91 91; 96 106

P r e s s u re (mm.) a U5.6 U8.5 50.7 5U.lt 5 6 .5 6 1 .7 6 3 .U 6U.2 6 5 .5 6 5 .5 6 5 .5 6 5 .8

Time ( h r s . ) 109 112 llU 118 130 135 1 38.5 1U3.5 15U.5 1 59.5 1 6 2 .5 166 1 79.5 18U

P re s s u re (mm.) 66.7 6 7 .1 6 7 .3 67.lt 67 .U 6 7 .9 6 7 .9 68.2 6 8 .8 6 8 .8 6 9 .3 6 8 .9 6 8 .9 6 9 .6

kl

T able 12

D issociation Pressure of TNB-benzene, Preparation No. 1, •with 97 Mole Per Cent Benzene 25.0° ; 0.1? Time ( h r s . ) 0 2 5 .5 1 8 .5 23 2 6 .5 2 9 .5 1*3

P re s s u re (mm.) 0 7.U 9 .8 1 3 .9 1 5 .3 1 6 .2 1 6 .6 1 7 .2

Time ( h r s . )

F fe s s u re (mm.)

1*8.5 5 5 .5 102 H 5 .5 126 139 11*6 1 5 0 .5

1 7 .8 1 8 .5 2 0 .8 20.7 2 1 .1 21.1* 21.9 22.7

T able 13 D is s o c ia tio n P r e s s u re o f TNB-benzene, P r e p a ra tio n No, 2, w ith 106 Mole P er Cent Benzene a t 2 5 .0 ° Time ( h r s . ) P re s s u re (mm.) 0 .0 8 l.lt 3 .6 5 .3 2 0 .5

*

9U.2 91.U

l6.k

7 3 .5 65.lt

a t 25. t 1 ° Time (Days) P re s s u re (mm,) 3

k 5 6 7 10 20 27 29 30 32

6 1 .2 5 9 .3 5 8 .2 5 6 .0 5 2 .9 U8.5 3 9 .8 * 38.7 3 8 .1 3 8 .5 3 8 .3

Conmencing on t h i s day t h e te m p e ra tu re was 25*0 Î 0 * 5 °.

U8

removed from t h e s o lv a t e .

F or P r e p a r a tio n No. 1 an e q u ilib riu m

p r e s s u r e o f 2 6 .0 mm. a p p e a rs t o have b e e n e s ta b lis h e d i n l e s s th a n 200 h o u rs (T a b le l i t ) .

However, f o r P r e p a r a tio n No. 2, t h e p r e s s u r e

o f 27*2 nmu was e s ta b li s h e d o n ly a f t e r a b o u t 30 days (T a b le 1 5 ). The re a s o n f o r t h i s d i f f e r e n c e i n r a t e , w hich a l s o ap p e a re d when d r iv in g o f f t h e b enzene from t h e compound, i s n o t known.

The

d i s s o c i a t i o n p r e s s u r e s o f P r e p a r a tio n No. 2 w ere d e te rm in e d f o r two o th e r mole p e rc e n ta g e s o f b e n z e n e .

F or 87 mole p e r c e n t benzene t h e

p r e s s u r e was a b o u t 26 .8 mm. a f t e r 33 days (T a b le 1 6 ) , and f o r 7It mole p e r c e n t t h e p r e s s u r e was a b o u t 25*9 nm. a f t e r 29 days (T able 1 7 ) . The d i f f e r e n c e s b etw een t h e s e p r e s s u r e s a r e j u s t beyond th e e r r o r 4 i n th e r e a d in g s ( - 0 .3 mm.). The sm all v a r i a t i o n may b e due t o a la c k o f e q u ilib riu m , t h e p re s e n c e o f a s o lu b le im p u rity , such as n a p h th a le n e , a s o lu t i o n o f TNB-benzene and TNB, o r a s o lu t io n o f benzene i n TNB.

One w ould n o t e x p e c t a sh a rp change i n p r e s s u r e a t

100 mole p e r c e n t o f b en zen e fo llo w e d b y a re g io n o f v e r y sm all p r e s s u r e change f o r a s o lu t i o n o f b e n z e n e i n TNB.

A con tin u o u s s o lu tio n

betw een TNB and TNB-benzene w ould p ro b a b ly in v o lv e a g r e a te r p r e s s u r e change th a n a c t u a l l y o ccu rs f o r such a l a r g e change i n com position (30 p e r c e n t ) .

T his le a v e s e i t h e r a la c k o f e q u ilib riu m o r a

s o lu b le im p u rity a s t h e cau se f o r t h e p r e s s u r e v a r i a t i o n . ca u ses ca n n o t b e d i f f e r e n t i a t e d fro m t h e p r e s e n t d a t a .

These

In e i t h e r

o f t h e s e tw o case s i t w ould mean t h a t th e r e i s a c r y s t a l l a t t i c e compound w ith l i t t l e o r no s o l u b i l i t y betw een TNB-benzene and TNB.

h9

T ab le lU D is s o c ia tio n P r e s s u re of TNB-benzene, P r e p a r a tio n No* 1* 97 Mole P e r C ent Benzene from t h e R ev e rse R e a c tio n a t 25*0° Time ( h r s , ) P ress* (mm.) Time ( h r s . ) P r e s s , (mm,)

0

1 min* 8U.5 73 2 6 .6

1 .2 U5,7 97 26.1*

8*3 3 3 .0

26 2 9 .1 11*5 2 6 .0

121 26.lt

3 0 .5 2 8 .6 198 26 .0

1*9 27.3 21*6 2 5 .9

T a b le 15 D is s o c ia tio n P r e s s u re o f TNB-benzene, P r e p a r a tio n No. 2 , w ith 96 Mole P er C ent Benzene a t 2 5 .0 I 0 .1 v Time (Days )

P r e s s , (mm.)

Time (D ays)

P r e s s , (mm.)

0 1 2 3 1* 5 7 8 10 12

8 3 .0 5 2 .2 1*7.6 1*5.1 1*3.5 1*1.0 39 .2 38.1* 36 .7 *

11* 16 20 21* 27 28 29 30 31 32

3 2 .9 * 2 9 .3 * 2 6 .0 2 8 .0 27.1* 2 7 .2 2 7 .0 27 .3

#

T em perature was to o high*

5o

Table 16 D issociation Pressure of TNB-benzene, Preparation No» 2, -with 87 Mole Per Cent Benzene at 25 #0 Time (Dggrs) 0 1 2 3 5 7 9 12 111

P r e s s , (mm.)

Time (D ays)

70 U0.7 37.lt 3U.0 3 0 .8 29 .8 2 9 .6 2 8 .9 2 8 .9

20 22 23 31 33 35 37 38

P r e s s , (mm.) 28.7 2 8 .1 2 7 .8 2 7 .6 Temp, was 26. 7# 2 6 .0 2 6 .8 26.9

T ab le 17 D is s o c ia tio n P r e s s u re of TNB-benzene, P r e p a r a tio n No . 2 , w ith 7h Mole P e r Cent Benzene a t 2 ^ .0 ± 0 .1 ^ Time (Days) 0 1 3 5

6 8 9

10 11



P r e s s , (mm.)

66 3 0 .7

2U.6 214.9 Temp, "mas 22° Temp, was 18° 2U.6 25 .3 25.lt

R eading ta k e n n in e h o u rs l a t e r .

Time (Days) 12 13 Ht 16 18 21 23 29 31

P r e s s , (mm.) Temp, was 22° 25.3 2 5 .5 25.7 2 5 .9 2 5 .9 26.1 25 .9 25 .9

51

The B eh av io r o f TNB-benzene m t h Aranonia,

The a d d i tio n o f

ammonia t o TKB-benzene w as c a r r i e d o u t t o d e te rm in e th e form o f TNB p r e s e n t i n t h e compound»

When 100 mole p e r c e n t o f ammonia was added

t o th e TNB-benzene, t h e ammonia w as abso rb ed a t room te m p e ra tu re w ith t h e l i b e r a t i o n o f l i t t l e benzene»

The r e s u l t i n g s o l i d w as, t h e r e f o r e ,

h e a te d a t 80° i n o r d e r t o d r iv e o f f t h e benzene»

Two d i f f e r e n t

ex p erim en ts (one w ith each p r e p a r a tio n ) showed t h a t th e r e s u l t i n g compound o f TNB-ammonia was t h e lo w p r e s s u r e form»

Thus, r e a c ti o n

a t room te m p e ra tu re had p ro d uced th e low p r e s s u r e form o f TNBammonia.

T h is shows t h a t t h e TNB i n t h e stiL vate was a d i f f e r e n t

form th a n t h a t i n h e a t - t r e a t e d TNB.

I t i s p o s s i b l e t h a t d r iv in g

o f f th e b enzene from t h e compound c o n ta in in g anmonia and b en zen e co u ld g iv e r i s e t o low p r e s s u re TNB-ammonia even i f t h e form p r e s e n t i n h e a i> tr e a te d TNB w ere p r e s e n t .

However, th e g r e a te r r e a c t i v i t y

o f TNB-benzene th a n h e a t - t r e a t e d TNB i n s o l u t i o n e lim in a te s t h i s p o s s ib ility . H e atin g a t 80° t o d r iv e o f f th e benzene was c a r r i e d o u t f o r a p e r io d o f a t l e a s t n in e h o u rs .

A c o n tr o l ex p erim en t u sin g h e a t-

t r e a t e d TNB w as, t h e r e f o r e , c a r r i e d o u t to b e c e r t a i n t h a t t h i s form o f TNB w ould n o t g iv e an a p p r e c ia b le amount o f th e low p r e s s u re f o m o f TNB-ammonia u n d er t h e c c n d itio n s o f t h e e x p e rim e n t.

The p ro ced u re

was th e same a s t h a t fo llo w e d w ith t h e b en zen e a d d itio n compound and ammonia.

The r e s u l t s showed t h a t a maximum o f n in e p e r cent

o f the TNB was f i n a l l y p r e s e n t as th e low p r e s s u r e form o f TNBammonia.

T h e re fo re , t h e p ro c e d u re u s e d w ould n o t r e s u l t i n an

a p p r e c ia b le amount o f low p r e s s u r e TNB-ammonia i f u n sy n m e tric a l TNB had b e e n p r e s e n t .

$2

The a b s o r p tio n o f ammonia by TUB-benzene m t h the l i b e r a t i o n o f l i t t l e b enzene was unexpected*

T h is o b s e rv a tio n was checked t y

s e a lin g TNB-benzene and ammonia ( i n ap p ro x im a te ly m olar r a t i o ) i n a tu b e w hich was k e p t a t 2$° f o r 170 hours*

At th e end of t h i s p e r io d

no l i q u i d (b en zen e) was o b se rv ed i n t h e tu b e .

Only a s m a ll amount

o f b enzene and anmonia w ere re c o v e re d when th e g a s e s were c o l le c te d i n t h e vacuum l i n e th ro u g h t h e b r e a k - o f f t i p a tta c h e d t o t h e tu b e . Hence, l i t t l e benzene was l i b e r a t e d upon a b s o rp tio n o f ammonia by TNB-benzene a t 2 £ °. The B eh av io r o f TNB, O btained upon L ib e r a tio n o f Benzene a t 8 0 °, w ith Ammonia*

The p u rp o se of t h i s ex p erim en t was to d eterm in e

th e p r o p e r t i e s o f t h e TNB o b ta in e d upon l i b e r a t i n g benzene from TNB-benzene.

Somewhat d i f f e r e n t r e s u l t s w ere o b ta in e d from th e two

p r e p a r a tio n s o f TNB-benzene.

The benzene i n t h e f i r s t p r e p a r a tio n

was d r iv e n o f f more e a s i l y th a n t h a t o f t h e seco n d .

Tlïhen t h e f i r s t

p r e p a r a tio n was u s e d , 88 p e r c e n t o f th e b en zen e was d r iv e n o f f a t 73° i n two h o u r s .

A m olar q u a n tity o f anm onia was added t o t h i s *

The s o l i d and gas w ere i n c o n ta c t f o r a s h o r t tim e a t room te m p e ra tu re b e fo re t h e te m p e ra tu re was r a is e d t o 8 0 °.

A f te r rem aining a t t h i s

te m p e ra tu re a b o u t f o u r h o u rs , th e r e s u l t s i n d i c a t e t h a t o n ly ab o u t p e r c e n t o f th e o r i g i n a l TNB was p r e s e n t a s th e low p r e s s u re TNB-ammonia,

T hus, a b o u t e le v e n p e r c e n t ^ I 0 0 ( 2 8 -1 9 )/(8 8 -7 2 7 o f th e

l i b e r a t e d TNB was a d i f f e r e n t form th a n t h a t i n h e a t - t r e a t e d TNB. The p ro c e d u re o f add in g 50 mole p e r c e n t ammonia t o th e TNB was u se d n e x t.

A f te r a b o u t 90 p e r c e n t o f th e benzene was l i b e r a t e d

53

Toy h e a tin g a t 80° f o r a b o u t 1*5 h o u rs , 50 m ole p e r cen t ammonia was added t o th e TNB. r e c o rd e d .

The change o f p r e s s u r e w ith tim e a t 80° was th e n

T h is e x p e rim en t showed t h a t ab o u t 28 mole p e r c e n t o f th e

TNB was th e sy m m e trica l fo rm .

Thus, ab o u t 13 p e r c e n t ^ 1 0 0 ( 2 8 -1 7 ) /

(9 0 -7 ) J o f th e l i b e r a t e d TNB was t h e sy m m etrical fo rm . Tlhen th e se c end p r e p a r a tio n was u s e d , o n ly 72 p e r c e n t o f th e benzene was l i b e r a t e d upon h e a ti n g f o r two h o u rs a t 8 00 (The TNB-benzene w ith o n e mole o f a b so rb ed ammonia l o s t 89 p e r c e n t o f i t s ben zen e i n two h o u r s a t 80 o .

T hus, t h e b en zen e was g iv e n up more r e a d i l y

a f t e r anmonia had b een a b so rb e d . ) .

I n t h i s experim ent th e anmonia

and s o l i d w ere k e p t i n c o n ta c t f o r s ix t e e n hours a t room te m p e r a tu re . The te m p e ra tu re was r a i s e d to 80° and th e m ix tu re k e p t i n c o n ta c t f o r n in e h o u r s .

Then t h e b enzene and anmonia in th e g as p h a se were

removed and f r a c t i o n a t e d .

From th e ammonia re c o v e re d , 91 p e r c e n t

o f th e TNB was c a lc u la te d a s p r e s e n t i n t h e low p r e s s u r e form o f TNB-ammonia.

T hus, a b o u t 8f> p e r c e n t (100 x

of t h e l i b e r a t e d

TNB was o f a d i f f e r e n t fo rm th a n t h a t i n h e a t - t r e a t e d TNB.

A

d u p l i c a t e ex p erim en t in d i c a t e d t h a t 90 p e r c e n t o f t h e TNB was p r e s e n t as t h e lo w p r e s s u r e TNB-ammonia.

Thus, a b o u t 8f> p e r cen t of th e

l i b e r a t e d TNB was o f a d i f f e r e n t form th a n t h a t i n h e a t - t r e a t e d TNB. F o r p ro p e r com parison o f r e s u l t s o f th e two p r e p a r a tio n s , th e same p e r c e n t b en zen e sh o u ld b e d r iv e n o f f . 88 p e r c e n t o f t h e b e n ze n e was l i b e r a t e d . 80°.

I n t h e n e x t experim ent T h is r e q u ir e d S3 hours a t

The same tr e a tm e n t w ith anmonia was fo llo w e d as f o r t h e c a s e s

when 72 p e r c e n t benzene was l i b e r a t e d .

The r e s u l t s in d ic a te d t h a t

5U

36 p e r c e n t o f th e o r i g i n a l TNB was p r e s e n t as t h e lo w p r e s s u re TNB-ammonia.

T hus, a b o u t 22 p e r c e n t

3 6 -1 8 ) /8 2 7

o f th e l i b e r a t e d

TNB had b ee n o f a d i f f e r e n t form th a n t h a t i n h e a t - t r e a t e d TNB. The r e s u l t s show t h a t two d i f f e r e n t p r e p a r a tio n s o f TNB-ammonia gave d i f f e r e n t amounts o f th e low p r e s s u r e f o r a o f TNB-ammonia. d isc re p a n c y i n t h e r e s u l t s h as n o t b e e n e x p la in e d .

The

I n any c a s e ,

each p r e p a r a tio n s t i l l had some sy m m etrical TNB when 88 p e r c e n t o f t h e benzene was l i b e r a t e d a t a r a t h e r low te m p e ra tu re .

I f sym m etrical

TNB i s p r e s e n t i n th e b enzene a d d itio n compound, th e n d r iv in g o f f t h e b enzene c o n v e rts 78 t o 88 p e r c e n t o f t h i s TNB to th e unsym m etrical fo rm . The d i f f e r e n c e f o r th e r a t e s a t w hich b en zen e was l i b e r a t e d from t h e two sam ples o f TNB-benzene i s n o t c l e a r .

E x p e rim en tal D e t a i l s P r e p a r a tio n and P u r i f i c a t i o n o f G ases. was condensed on sodium w ith d ry i c e .

Anhydrous ta n k ammonia

The ammonia was th e n a d m itted

in to t h e vacuum l i n e where i t was th o ro u g h ly pumped o u t u s in g a l i q u i d n itr o g e n t r a p .

Tank hydrogen c h lo r id e was in tro d u c e d in to

t h e vacuum l i n e , f r a c t i o n a t e d th ro u g h d ry i c e t r a p s . and f i n a l l y pumped o u t u s in g a l i q u i d n itr o g e n t r a p . D is s o c ia tio n P r e s s u re M easurem ents o f TNB-ammonia.

A ll e x p e ri­

m ents w ith s o l i d TNB and gaseous ammonia were made i n th e a p p a ra tu s shown i n F ig u re 8 .

A w eighed q u a n tity o f TNB was in tro d u c e d in t o

56

t h e sm all b u lb and t h e tu b e s e a l e d .

The tu b e was e v acu ated th ro u g h

t h e manometer and t h e f l o a t v a lv e .

Ammonia was th e n m easured o u t as

a gas i n t h e h ig h vacuum l i n e an d condensed i n t h e tu b e w ith l i q u i d n itr o g e n .

M ercury was t h e n r a i s e d i n t o th e manometer and t h e e q u i l i ­

b rium p r e s s u r e s d ev elo p ed w ere m easured on th e m ercury u s in g a m illim e te r s c a l e . H igher te m p e ra tu re s w ere m a in ta in e d w ith a c o n s ta n t te m p e ra tu re b a th made from a 1 - l i t e r B e r z e liu s b e a k e r .

T h is was wrapped f i r s t

w ith a s b e s to s p a p e r , t h e n a 22 f t . c o i l o f No. 22 n i chrome w ir e , and f i n a l l y w ith m agnesia p ip e c o v e rin g .

The te n p s r a tu r e was

c o n tr o lle d by a d j u s t i n g t h e v o lta g e a c ro s s t h e w ir e .

W ith a s t i r r e r

and a cover on to p o f t h e b a th , th e te n p e r a tu r e co u ld b e c o n tr o lle d t o 0 . 1° f o r a t l e a s t one hour. The p ro ce d u re f o r t h e s tu d i e s o f t h e b e h a v io r o f TNB upon a d d itio n o f 50 mole p e r c e n t ammonia was as f o llo w s .

A weighed

sam ple o f TNB was in tro d u c e d in to th e b u lb of t h e a p p a ra tu s shown i n F ig u re 8 , t h e tu b e was s e a le d , and th e a p p a ra tu s was e v a c u a te d . A m easured q u a n t i t y o f ammonia was condensed i n th e b u lb u s in g l i q u i d n it r o g e n .

Two m in u tes a f t e r b e in g p la c e d a t th e b u lb th e

l i q u i d n i tr o g e n was rem oved.

F i n a l l y , two m inutes a f t e r rem oving

t h e l i q u i d n i t r o g e n t h e c o n s ta n t te m p e ra tu re b a th a t 80° was p la c e d a t t h e b u lb .

T h is was ta k e n as th e zero tim e .

th e n made a t v a r io u s tim e s .

P r e s s u re re a d in g s were

57

An A ttem pt t o P re p a re Sym m etrical TNB. i n F ig u re 8 was u sed f o r t h i s e x p e rim e n t.

The a p p a ra tu s shovm.

The TNB-ammonia was p re p a re d

from 0 .8 5 3 g- o f TNB and U8 .8 m l. (100 mole p e r c e n t) of ammonia, hydrogen c h l o r id e , lip .6 m l. was m easured o u t.

The volume e n c lo se d

by th e m ercury o f t h e manometer was n o t s u f f i c i e n t to accanmodate t h i s q u a n tity o f g a s so o n ly 9»1 m l. was added to t h e TNB. D is s o c ia tio n P r e s s u re M easurements on TKB-benzene.

The

d i s s o c i a t i o n p r e s s u re o f TNB-benzene ( P r e p a ra tio n No. 1) a t 25° was d e term in e d u s in g t h e a p p a ra tu s shown i n F ig u re 9 .

The b u lb a ,

w hich c o n ta in e d 0 .9 6 ? g . o f t h e compound, was p la c e d i n a c o n s ta n t te m p e ra tu re b a t h and t h e p r e s s u r e was re a d on t h e manometer b . T ab le 10 g iv e s th e r e s u l t s .

The rem oval o f benzene was made th ro u g h

tu b e c w hich was c o n n ec te d t o th e h ig h vacuum l i n e th ro u g h th e tu b e b re a k e r.

The t i p was b ro k en and th e benzene removed to th e h ig h

vacuum l i n e .

The volume removed was I4..6 m l. (re d u c e d t o 0° C. and

760 mm.) w hich i s 10 p e r c e n t o f t h e b e n zen e.

A d ry i c e tr a p was

th e n p la c e d a t b u lb a and th e tu b e c was s e a l e d - o f f from th e vacuum lin e .

The b u lb was a g a in p la c e d i n a 25° b a th and th e p re s s u re s

re c o rd e d .

T hese r e s u l t s a r e re c o rd e d i n T ab le 12.

T h is sam ple,

c o n ta in in g 97 mole p e r c e n t b e n z e n e , was n e x t used t o d e te rm in e th e d is s o c ia tio n p re ssu re b y th e re v e rse r e a c tio n .

The sam ple was h e a te d

a t 80° f o r 20 m in u tes when a c o n s id e ra b le q u a n tity o f l i q u i d had condensed i n th e tu b e and on t h e m ercu ry .

D ry i c e was u sed to condense

th e benzene back on th e s o l i d and t h e b u lb was p la c e d i n a b a th a t 25°. The r e s u l t s f o r t h i s ex p erim en t a r e re c o rd e d i n T able l l u

58

The d i s s o c i a t i o n p r e s s u re a t 39° was d eterm in ed u s in g t h e a p p a ra tu s shovm i n F ig u re 8 .

The c o n s ta n t te m p e r a tu re was s u p p lie d

by th e v a p o r o f b o i l i n g m eth y len ej t h i s a p p a ra tu s i s shovm i n F ig u re 10.

The compound ( P r e p a r a tio n No. 1) p la c e d i n th e b u lb w eighed

0 .973 g*

The r e s u l t s f o r t h i s r u n are g iv e n i n T ab le 11.

The d i s s o c i a t i o n p r e s s u re o f P r e p a r a tio n No. 2 from t h e r e v e r s e d i r e c t i o n was a l s o d e term in e d i n th e a p p a ra tu s shown i n F ig u re 8 . The te m p e ra tu re was m a in ta in e d betw een 25 and 27° by w a te r i n a dew ar. The dewar was f i l l e d d a i l y w ith w a te r a t 2 5 .0 ° . t i o n No. 2 ) in tro d u c e d w eighed 0.955 g .

The compound (P re p a ra ­

H eating a t 80° f o r U0 m in u tes

l i b e r a t e d 2 3 .6 m l. (52 p e r c e n t) b e n zen e.

The benzene was im m ed iately

added b ac k t o th e compound by condensing w ith l i q u i d n itr o g e n .

The

m ercury i n t h e manometer was r a i s e d and th e b u lb warmed t o room te m p e ra tu re .

The benzene was r a p i d ly ab so rb ed a s shown i n T able 1 3 .

The d i s s o c i a t i o n p re s s u re upon rem oval o f v a r io u s am ounts o f benzene was th e n d e te rm in e d u s in g a n o th e r sample o f P r e p a ra tio n No. 2

T h is

tim e a therm o s t a t i c a l l y c o n tr o lle d w a te r b a th was used t o m a in ta in a te m p e ra tu re o f 2 5 .0 t 0 .1 ° . w id ely fro m t h i s v a lu e .

S e v e ra l tim e s th e te m p e ra tu re d e p a rte d

I t was l a t e r found t h a t a lo o s e c o n n e c tio n

cau sed i n t e r m i t t e n t f a i l u r e o f th e h e a te r t o o p e r a te g iv in g r i s e to low te m p e r a tu re s .

The h ig h te m p e ra tu re s were a p p a r e n tly cau sed by

im proper f u n c tio n in g o f t h e r e l a y .

The sam ple used w eighed 0 .909 g.

Benzene, U.29 m l., was rsn o v e d le a v in g 96 m ole p e r c e n t. o b ta in e d f o r t h i s p e rc e n ta g e a r e g iv en i n T a b le 15. was rem oved, 3 .8 2 m l., le a v in g 87 p e r c e n t.

The r e s u l t s

More benzene

The r e s u l t s f o r t h i s

59

p e rc e n ta g e a r e g iv en i n T a b le 1 6 .

F i n a l l y , 5 .7 9 m l. o f b enzene

was rem oved le a v in g 7U p e r c e n t i n th e compound.

The r e s u l t s f o r t h i s

ru n a r e g iv e n i n T a b le 1 7 . The B eh av io r o f TNB-benzene w ith Ammonia.

These ex p erim en ts

w ere c a r r i e d o u t i n th e a p p a ra tu s shown i n F ig u re 8.

Ammonia, U5.1 m l.,

(100 mole p e r c e n t b ased on O.787 g . o f TNB i n t h e compound) was added t o 0 .957 g . o f t h e a d d itio n compound ( P r e p a ra tio n No. 1 ) i n th e b u lb a .

Upon warming t o room te m p e r a tu re , th e gas o ccu p ied th e

w hole volume (115 m l.) from t h e b u lb t o th e f l o a t v a lv e d .

A f te r

re m ain in g i n c o n ta c t f o r 6 m in u tes th e g as was condensed i n tu b e b and t r a n s f e r r e d t o t h e f r a c t i o n a t i n g sy stem . o n ly ab o u t 0.U m l. was b e n ze n e.

The gas was f r a c t io n a te d ;

The ammonia was r e tu r n e d to t h e b u lb .

Again a f t e r 6 m in u tes a t 31° th e g as was removed and f r a c t i o n a t e d . About 6U p e r c e n t o f t h e o r i g i n a l ammonia added was o b ta in e d w h ile o n ly a t o t a l o f l.U m l. o f b en zen e was l i b e r a t e d . r e tu r n e d to t h e b u lb .

The ammonia was

Now t h e g ases w ere c o n fin e d i n th e volume

betw een th e b u lb and th e m ercury o f t h e manometer c . were k e p t i n c o n ta c t f o r 100 m in u te s .

The m a te r ia ls

The gas was ranoved and f r a c t i o n a t e d .

The re c o v e re d m a t e r ia ls c o n s is te d o f 1 2 .5 m l. (28 p e r c e n t o f th e o r i g i n a l am ount) ammonia and 3 .0 m l. b en zen e.

The ammonia was r e tu r n e d

t o th e b u lb and th e m a te r ia ls l e f t i n c o n ta c t f o r 16 hours a t 3 0 °. The g a ses w ere a g a in f r a c t i o n a t e d and t h e ammonia (6 m l.) r e tu r n e d o f th e TNB-benzene.

Only a t o t a l o f 5 m l. benzene had been re c o v e re d

from th e r e a c t i o n m ix tu re .

The TNB-benzene and ammonia w ere th e n l e f t

a t 80° f o r a b o u t 16 h o u rs t o d r i v e - o f f th e b e n zen e.

F i r s t an ic e b a th

60

and th e n a d ry i c e b a t h was k e p t a t tu b e b t o remove th e benzene from th e gas p h a s e .

At th e end

mm. w ith t h e d r y i c e t r a p a t b .

o f t h i s p e r io d t h e p r e s s u r e was 0 .0 S in c e ammonia h as a

v ap o r p r e s s u r e

o f UU mm. a t d ry i c e te m p e ra tu re , t h i s i n d i c a t e s t h a t a i l had r e a c te d . F u rth erm o re, t h i s i n d i c a t e s t h a t t h e p r e s s u r e o f th e TNB-NH3 o b ta in e d i n t h i s way h a s a p r e s s u r e o f 0 .0 mm. The b en zen e condensed i n tu b e b was removed t o th e vacuum l i n e f o r m easurem ent.

The t o t a l amount o f b en z e n e c o lle c te d was UU-6 m l.

compared t o U8 .8 m l. e x p e c te d f o r 107 p e r c e n t benzene i n t h e compound. The d i s s o c i a t i o n p r e s s u r e s o f t h e ammonia a d d itio n compound w ere th e n d e te rm in e d a t h ig h e r te m p e r a tu re s .

The r e s u l t s , g iv e n i n

T a b le 1 8 , c l e a r l y i n d i c a t e t h a t t h e low p r e s s u r e form was o b ta in e d . The above ex p erim en t was

r e p e a te d u s in g 0.983

No. 2 and U6 .8 m l. (101 mole p e r c e n t b a se d on compound) o f anm onia.

0.810

g. o f P r e p a ra tio n g . o f TNB i n th e

The ammonia was added t o t h e benzene compound

and l e f t f o r two h o u rs a t 3 1 ° i n th e volume betw een t h e b u lb and t h e m ercury f l o a t v a l u e .

The gas was th e n t r a n s f e r r e d to th e f r a c t i o n a t i n g

system and f r a c t i o n a t e d .

The ammonia re c o v e re d was 1 2 .8 m l. (7 2 .6

p e r cent o f th e ammonia had been a b so rb e d ) and th e b enzene re c o v e re d was 1 .2 m l.

The ammonia was r e t u r n e d to th e TNB-benzene and c o n fin ed

i n t h e volume betw een t h e b u lb and t h e m ercury o f t h e manometer f o r I k h o u rs a t 27 t o 3 0 °.

The gas was th e n removed and f r a c t i o n a t e d .

This gave 1 .7 m l. ammonia (96 p e r c e n t o f t h e ammonia was a b so rb e d ) and t o t a l o f 3*0 m l, b e n z e n e .

The ammonia was r e tu r n e d t o th e s o li d

and t h e m ix tu re was h e a te d a t 80° f o r two h o u rs w ith an i c e b a th a t tu b e b .

The v o l a t i l e m a t e r ia ls w ere removed and f r a c t i o n a t e d .

This

61

T ab le 18 D is s o c ia tio n P r e s s u re s o f TNB-ammonia O b tain ed by R e a c tin g TNB-benzene and Ammonia a t 30° and 86°

Time ( h r s . )

0 1.2 2.3 U.5 Removed 5.0 9 .0

22.0 22.5 23.0 23.2

g as o v er compound a t

P r e s s u re (mm,)

li|0°

1.8 2.2 11 111.8 8.8 io.U 12.3 36.1 37.8 37.6

T em perature

110° no ll|0 UiO

ib P

ll|0 lllO 160 160 160

62

gave 0 .6 m l. ammonia ( 98 .7 p e r c e n t had added) and a t o t a l o f 146.9 m l. (95 p e r c e n t o f t h e t h e o r e t i c a l ) b en z e n e .

Of t h i s b en zen e U3.9

m l. (89 p e r c e n t) was l i b e r a t e d a t 80° i n tw o h o u r s .

The am nonia was

added b a c k t o th e s o lid and t h e m ix tu re h e a te d f o r an a d d itio n a l 7 h o u rs a t 80° p la c in g a d r y i c e b a th a t tu b e b a f t e r 3 h o u rs .

The

gas was th e n removed and f r a c t i o n a t e d y i e l d i n g 0 .8 m l. ammonia (9 8 .3 p e r c e n t had added) and a t o t a l o f U7.9 m l. (U9.6 m l. was e x p e cted f o r 106 p e r c e n t b en zen e i n t h e compound) b en zen e.

The

d i s s o c i a t i o n p r e s s u r e o f th e r e s u l t i n g amnonia a d d itio n compound a t II4O0 was a b o u t 10 mm., h en ce, th e lo w p r e s s u r e fo rm o f TNB-ammonia was a g a in i s o l a t e d . A c o n tr o l ex p erim en t w ith TNB was c a r r i e d o u t u s in g e s s e n t i a l l y th e above p ro c e d u re .

To 0 .8 1 6 g . o f TNB i n "die b u lb was added I46.3

m l. ( 99*3 p e r c e n t o f th e t h e o r e t i c a l ) ammonia an d t h e m ercury f l o a t v a lv e d was r a i s e d .

A f te r two h o u rs a t 27° th e ammonia rem oved m easured

8 .I4 m l. (81 p e r c e n t o f th e ammonia was a b s o rb e d ).

The ammonia was

added back t o th e TNB and t h e m ercury o f t h e manometer was r a i s e d .

A f te r

U4 h ours a t 2h t o 27° t h e ammonia was rem oved, and 7*0 m l. was re c o v e re d . The ammonia was ad d ed b a c k t o th e TNB and k e p t a t 80° f o r 9 h o u rs . th e end o f t h i s tim e t h e p r e s s u re was a b o u t 170 mm.

At

The amnonia over

th e TNB was ran o v ed u n t i l t h e p r e s s u r e dropped t o ab o u t lU mm. volume o f ammonia re c o v e re d was 2 9 .2 m l. (6 2 .7 p e r c e n t ) .

The

The

te m p e ra tu re was th e n r a i s e d to 120° and ammonia was removed u n t i l th e p r e s s u r e was a b o u t U nm.

The volume o f ammonia re c o v e re d was Ip..9

m l. ( 9 .I4 p e r c e n t o f th e t h e o r e c t i c a l had r e a c t e d ) .

TShen th e te m p e ra tu re

was r a i s e d t o llj.0 0 and rem oval o f amnonia dropped t h e p r e s s u r e over

63

th e TNB t o 10 mm. a t o t a l o f 1+3.9 m l. had been c o l l e c t e d .

T his

c o rre sp o n d s t o 5 .2 p e r c e n t o f th e t h e o r e t i c a l amount o f ammonia h a v in g r e a c t e d .

T hus, b etw een f i v e and n in e p e r c e n t o f th e TNB

was c o n v e rte d t o TNB-ammonia. The p u rp o se of t h e f o llo w in g ex p erim en t was to d e te rm in e w h eth er an a p p r e c ia b le amount o f b enzene was l i b e r a t e d when ammonia was added t o TNB-benzene a t o r d in a ry te m p e r a tu r e s . was c o n s tr u c te d f o r t h i s p u rp o s e .

The tu b e shown i n F ig u re 11

The volume was d e te rm in e d t o be

33 m l. by f i l l i n g w ith a known volume o f w a te r up t o t h e s e a l - o f f b . A sam ple o f 0 .9 7 6 g . TNB-benzene ( P r e p a r a tio n No. 1 ) was in tro d u c e d th ro u g h tu b e a w hich was th e n s e a l e d - o f f .

The tu b e was co nnected

to th e vacuum l i n e by th e b a l l j o i n t and e v a c u a te d .

Then 1+6.U m l. ammonia

(101 p e r c e n t o f th e t h e o r e t i c a l ) was condensed on th e TNB-benzene and t h e tu b e s e a le d o f f a t b .

The tu b e was k e p t a t 25° f o r 170 h o u rs .

At t h e end o f t h i s p e r io d t h e r e was no v i s i b l e l i q u i d co n d en sate in d ic a tin g t h a t v e r y l i t t l e b enzene had b een d is p la c e d .

The gas in

th e tu b e was removed t o t h e h ig h vacuum l i n e th ro u g h b r a k e - o f f tu b e £.

Only a b o u t 1 .6 m l. o f g as was re c o v e re d from th e tu b e ; o f t h i s 1 .2

m l. was ammonia (Some gas may have b e e n l o s t th ro u g h h av in g t h e pump on when rem oving the g ases t o a l i q u i d a i r t r a p ) . re c o v e re d from th e tu b e and w eighed.

The s o lid was

The w e ig h t o f s o l i d p lu s th e

w e ig h t c a l c u l a t e d f o r t h e c o l l e c t e d g as was 1.00)+ g.

The w eight

o f TNB p lu s ammonia a t s t a r t was 1 .0 1 1 g . ( ap p ro x im a te ly 0.177 g. o f benzene was p r e s e n t i n t h e TNB-benzene).

These r e s u l t s c l e a r l y

i n d i c a t e t h a t v e iy l i t t l e benzene was l i b e r a t e d upon a b s o rp tio n of most o f t h e ammonia b y TNB-benzene a t 2 5 °.

a boiling liquid

temperature

constant

by

tor maintaining

Apparatus

Fig. 10.

and

for sealing

n.

TNB-benzene

Apparatus

rig

together

ammonia

64

65

The B eh a v io r o f TNB, O btained upon L ib e r a tio n o f Benzene a t 80°, Twith Ammonia»

The a p p a ra tu s shcrnn i n F ig u re 8 was used f o r th e

fo llo w in g e x p e rim e n ts .

A sample o f P r e p a r a tio n No* 1 , 0 .9 5 8 g . , was

p la c e d i n t h e b u lb and t h e b en zen e w as d r iv e n - o f f a t 73° f o r two h o u r s . T his l i b e r a t e d h3 m l. (88 p e r c e n t o f t h e t h e o r e t i c a l ) b e n z e n e .

Ammonia,

U5#7 m l. (10U mole p e r c e n t o f t h e t h e o r e t i c a l ) , was th e n added. A f te r a b o u t 10 m in u tes a t room te m p e r a tu re , th e te m p e ra tu re was in c r e a s e d t o 80° and h e ld f o r fo u r h o u rs . was removed and f r a c t i o n a t e d .

The gas o v er th e s o l i d

T h is gave 1 8 .8 m l. ammonia and b ro u g h t

th e t o t a l amount o f b en zen e t o 1*6 m l. (91* p e r c e n t o f th e t h e o r e t i c a l ) . The te m p e ra tu re was r a i s e d to 110o, and gas was removed from th e system u n t i l th e p r e s s u r e was ab o u t 5 mm.

The t o t a l volum e o f ammonia re c o v e re d

was 3 2 .9 m l . , th u s 28 p e r c e n t o f t h e TNB had com bined w ith ammonia. T h is r e p r e s e n ts a maximum v a lu e s in c e t h e p r e s s u r e o f 5 nm. a t 110° i s h ig h f o r TNB-amnonia. The p ro c e d u re u s in g 50 mole p er c e n t ammonia was n e x t u s e d . A sample o f 0.982 g . o f P r e p a r a tio n No. 1 was h e a te d a t 80° f o r 1 .5 h o u rs w ith a n i c e b a th a t tu b e b (F ig u re 8 ) .

The b enzene re c o v e re d

was 1*6.9 m l. (90 p e r c e n t o f t h e t h e o r e t i c a l ) .

To th e s o lid i n t h e

b u lb was added 2 2 .8 m l. (1*9*5 mole p e r c e n t) ammonia and t h e change o f p r e s s u r e w ith tim e re c o rd e d .

A d ry i c e b a th was p la c e d a t th e

tu b e b t o rem ove any b enzene t h a t was l i b e r a t e d . i n T ab le 19*

The d a ta a r e g iv en

The v a lu e a t 120 m in u tes co rre sp o n d s ro u g h ly t o th e

c a l i b r a t i o n c u rv e f o r 30 p e r c e n t ammonia, hence ab o u t 28 mole p e r c e n t / “l 0 0 (1*9.5 — x ) / ( 100 - x)= 30, w here x = mole p e r c e n t of TNB t h a t i s t h e sy m m e trica l f o r m , / of t h e sy m m etrical TNB was p r e s e n t .

Table 19 V a r ia tio n o f P r e s s u re w ith Time o f TNB-ammonia P re p a re d from TNB F r e s h ly F reed o f Benzene ----------------------- a t l T d B ----------------------------------

T em perature - 80° Time (m in. )

1

2

U

P re s s u re (mm.)

1 3 .U 1 3 .6

8

1 5 .9

17

Time (m in. )

22

26

3h

P re s s u re (ram,)

1 2 .0

1 1 .3

1 0 .5

Time (ra in .) P re s s u re (mm.)

#

93 8 .6

120 8 .5

U

15

17^

1 6 .6

1*2 9 .9

126 7 .8

P la c e d d ry i c e b a t h a t tu b e b ( F ig . 8 ) .

63 9.1*

67

A sam ple o f P r e p a r a tio n No, 2 , 0 ,979 g»* was p la c e d i n t h e b u lb and h e a te d a t 80° f o r tw o h o u rs w ith an i c e b a th a t tu b e b .

The

volum e o f benzene l i b e r a t e d was 3 5 .7 m l. (72 p e r c e n t o f t h e t h e o r e t i c a l ) . Ammonia, U6.U m l. (101 p e r c e n t of th e t h e o r e t i c a l ) , was added t o th e TNB-benzene and l e f t a t room te m p e ra tu re f o r tw o h o u rs . th e n rem oved and f r a c t i o n a t e d .

The gas was

The volume o f ammonia re c o v e re d was

8 .6 m l. (8 1 .3 p e r c e n t o f t h e TNB had abso rb ed am nonia). The ammonia was added b ack t o (a b o u t 3 0 ° )•

t h e s o l i d and l e f t f o r lU hours a t room te m p e ra tu re

The g ases w ere a g a in removed and f r a c t i o n a t e d .

The volume

o f ammonia re c o v e re d was 3 .3 m l. and th e t o t a l volume o f benzene c o lle c te d was 3 7 .3 m l. f o r two h o u rs . re tu rn e d .

The ammonia was r e tu rn e d and t h e c o n te n ts h e a te d a t 80° The gas was removed and f r a c t i o n a t e d and th e ammonia

The benzene c o l l e c t e d so f a r t o t a l e d U7.U m l. (96 p e r c e n t

of th e t h e o r e t i c a l ) .

The b u lb was h e a te d f o r an a d d it io n a l sev en

h o u rs a t 8 0 °, th e n th e gas over th e s o l i d was removed u n t i l th e p r e s s u r e o v er t h e TNB was 1 mm.

The te m p e ra tu re was r a i s e d t o 100°

and gas a g a in removed u n t i l th e p r e s s u r e over th e TNB was 1 mm.

The

p r e s s u r e was 1 1 .U mm. when t h e te m p e ra tu re was r a i s e d t o 1U0°.

The

t o t a l amount o f ammonia re c o v e re d from th e s o l i d was U.8 m l., so 91 p e r c e n t o f t h e TNB was p r e s e n t as th e low p r e s s u r e form of TNB-ammom. a . T h is ex p erim en t was re p e a te d w ith 0.979 g. o f TNB-benzene and U6.U m l. (101 p e r c e n t o f t h e t h e o r e t i c a l ) ammonia.

The benzene

d r iv e n o f f i n two h o u rs a t 80° was 3 6 .0 m l. (73 p e r c e n t o f t h e th e o re tic a l).

I n t h i s c ase t h e ammonia was l e f t i n c o n ta c t w ith

t h e s o l i d f o r 16 hours a t room te m p e ra tu re (a b o u t 2 8 ° ) .

7/hen th e

68

gas was removed and f r a c t i o n a t e d 3 .1 m l. o f ammonia (93 p e r c e n t had r e a c t e d ) was r e c o v e r e d .

T h is was r e tu r n e d to th e s o l i d and h e a te d

a t 80° f o r two h o u r s .

The gas ov er t h e s o l i d was f r a c t i o n a t e d and

th e ammonia r e t u r n e d .

The t o t a l amount o f benzene c o lle c te d was I46.9

m l. (95 p e r c e n t o f t h e t h e o r e t i c a l ) .

The s o l i d and ammonia were

h e a te d f o r seven h o u rs a t 80° , and t h e g as was removed u n t i l th e p r e s s u r e dropped t o 3 mm.

The te m p e ra tu re was th e n r a i s e d t o 100°

and t h e g a s was ran o v ed u n t i l th e p r e s s u r e o v e r t h e TNB was ab o u t 2 mm.

The p r e s s u re f i n a l l y , o b ta in e d a t lU0° was 13 mm.

The t o t a l

amount o f ammonia t h a t had b een re c o v e re d was 5*1 m l., hence 90 p e r c e n t o f t h e TNB was p r e s e n t as t h e lo w p r e s s u r e f o m o f TNB-ammonia. A sam ple, 0.9 7 9 g . o f P r e p a r a tio n No. 2, was h e a te d f o r 53 h o u rs to d r iv e o f f 1l3.8 m l. (88 p e r c e n t o f th e t h e o r e t i c a l ) b en z e n e . Ammonia, 146.6 m l. (102 p e r c e n t ) , was th e n added an d l e f t a t room te m p e ra tu re (26 to 29°) f o r 16 h o u rs . and th e ammonia r e tu r n e d t o t h e s o l i d .

The gas was rem oved, f r a c t i o n a t e d , A f te r h e a tin g f o r two h ours

a t 80° th e gas was removed and f r a c t i o n a t e d .

The volum e o f ammonia

re c o v e re d was 1 0 .0 m l. (80 p e r c e n t had b e e n absorbed) and t h e volume o f benzene c o l l e c t e d was I46.7 m l, ( 9I4- p e r c e n t) .

The ammonia was

r e tu r n e d t o th e s o l i d and h e a te d f o r a n a d d i tio n a l 7 h o u rs a t 80°. The g as was th e n removed u n t i l th e p r e s s u r e o v er t h e s o lid was about 2 mm. a t 8 0 °. a t 3 mm..

Gas was rem oved a t 120° u n t i l th e p r e s s u r e rem ained

The t o t a l volume o f ammonia c o l l e c t e d was 3 0 .0 m l., hence

36 p e r c e n t o f t h e TNB was p r e s e n t as t h e low p r e s s u r e f orm o f TNBammonia.

69

CHAPTER IV THE NATURE OF THE PRODUCT OBTAINED BY RECRYSTALLIZING HEAT-TREATED TRI-ALPHA-NAPHTHYLBORON FROM VARIOUS SOLVENTS AND THE SOLUBILITY OF TRI-ALPHA-NAPHTHYLBORON

R e c r y s t a l l i z a t i o n o f H e a t-T re a te d TNB from V ario u s S o lv e n ts I n tr o d u c t i o n .

S in c e TNB upon c r y s t a l l i z a t i o n from benzene

g iv e s a s t a b l e o n e -to -o n e compound, i t was d e c id e d t o f i n d o th e r s o lv e n ts w ith w h ich TNB w ould com bine.

By p ro p er s e l e c t i o n o f s o lv e n ts

i t was hoped t o c o r r e l a t e t h e e f f e c t o f s i z e , shape and c o n s ti t u t i o n o f t h e s o lv e n t m o lecu le w i t h compound fo rm a tio n . i n t e r e s t from a n o th e r s ta n d p o in t.

This -work was o f

I n a r e c e n t a r t i c l e , H. M. P ow ell

(2 0 ) d is c u s s e d u n u s u a l compounds, d is c o v e re d th ro u g h X -ray a n a ly s is , w hich e x i s t o n ly i n t h e s o li d s t a t e .

These a r e form ed when s o lv e n t

o r gaseous m o le c u le s a r e e n tra p p e d and h e ld i n h o le s o f t h e c r y s t a l upon c r y s t a l l i z a t i o n .

The f o r c e s le a d in g to th e s e compounds a re

n o t n e c e s s a r i l y t h e norm al v a le n c e or p o la r f o r c e s , b u t t h e compound r e s u l t s fro m t h e c la w lik e e n c lo s u re o f t h e s o lv e n t o r gaseous m o le c u le s, i n th e s e h o le s , by t h e m o lecu les of t h e c r y s t a l . he named t h e s e " c l a t h r a t e compounds” .

For t h i s re a s o n

I n o r d e r t o f r e e th e e n c lo se d

m o lecu les r u p tu r e o f t h e c r y s t a l l a t t i c e i s n e c e s s a r y .

I t ap p eared

t h a t a s im i l a r s i t u a t i o n may e x i s t i n t h e benzene s o lv a te o f TNB. The two c r y s t a l l i n e fo rm s o f TNB may d i f f e r i n t h a t one h as th e space

70

( o r h o le s ) a v a i l a b l e f o r t h e e n c lo s u re o f o th e r m o le c u le s, w hereas t h e o th e r d oes n o t .

I t would f o llo w th e n t h a t t h e TNB o f t h e

benzene s o lv a te h as th e s e h o le s w hich a r e o f su ch s i z e and shape a s t o a c c o m o d a te a m o lecu le w ith t h e s i z e and shape o f b e n z e n e . The s o lv e n ts chosen f o r i n v e s t i g a t i o n w ere b en zen e, to lu e n e , carbon t e t r a c h l o r i d e , e t h e r , te tr a h y d r o f u r a n , th io p h e n e , and f u r an . Two p ro c e d u re s w ere u sed f o r t h i s s tu d y .

I n th e f i r s t , th e

s o l i d w as d is s o lv e d i n t h e s o lv e n t w h ich was th e n rem oved u n d er red u c ed p r e s s u r e a t room te m p e ra tu re *

The d i f f e r e n c e i n w eig h t o f

th e s o l i d b e f o re an d a f t e r t h i s tr e a tm e n t showed w h e th e r a compound was fo rm e d .

I n t h e se c o n d p ro c e d u re a known w eig h t o f s o l i d was

d is s o lv e d i n a known w e ig h t of s o lv e n t .

Known q u a n t i t i e s o f th e

s o lv e n t w ere removed fro m t h e s o l u t i o n and th e v a p o r p r e s s u r e o f t h e s o lu t i o n was re c o rd e d a f t e r e a c h re m o v a l.

The p r e s s u re -c o m p o s itio n

cu rv e p l o t t e d fro m th e s e d a t a showed w h e th e r compound fo rm a tio n o c c u rre d . The second p ro c e d u re a ls o en a b le d a s e m i- q u a n tita tiv e c a l c u l a t i o n of th e s o lu b ility .

In t h i s c o n n e c tio n o th e r s o l u b i l i t y d a ta a r e

a ls o p r e s e n te d h e r e . The Q u a l i t a t i v e R e s u lts o f P ro ced u re No* 1 . o b ta in e d u s in g t h i s p ro c e d u re a r e g iv e n i n T a b le 20.

The r e s u l t s The headings

a r e s e l f e x p la n a to ry e x c e p t, p e rh a p s , f o r t h e l a s t two colum ns.

Under

" A fte r E v a c u a tio n a t 1 t o 2 mm.— F u r th e r " , th e w eig h t re c o rd e d i s f o r th e number o f a d d i t i o n a l h o u rs o f e v a c u a tio n g iv e n n e x t to th e w e ig h t.

Thus, i n t h e b enzene tr e a tm e n t, 2.531 g . o f s o l i d w ere l e f t

71

f e g

P i EH

1A H O 6) r—1 rH rH O O Q n 0 9

No Solvents by Procedure of TNB -with Various Data on Treatment

O

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CM CM

CM H

O

=H

I H

CM H

S S3 0

1 o

co

72

a f t e r 23 h o u rs o f e v a c u a tio n f o llo w in g th e p re v io u s w eighing (2 ,5 3 5 g« ) . The number of m oles o f s o lv e n t re m a in in g p e r mole of TNB i s g iv e n i n th e l a s t colum n.

T h is w as o b ta in e d b y d iv id in g t h e w e ig h t o f s o lv e n t

re m a in in g w ith t h e TNB by t h e w e ig h t ex p ected to rem ain f o r a o n e -to -o n e compound.

Thus, f o r b en zen e t h e w e ig h t rem ain in g was 0.1*63 g . (2 .5 3 1 -

2 .0 6 8 ) w h ile t h e w e ig h t e x p e c te d was 0.1*12 g. (2.1*80-2.068).

D iv id in g

t h e 0.1*63 .by 0.1*12 g iv e s 1 .1 2 m oles o f b en zen e f o r each m ole o f TNB a s r e c o rd e d i n t h e T a b le . The v a lu e s i n th e l a s t column show t h a t benzene and th io p h e n e a r e t h e o n ly s o lv e n ts w hich e x h ib it compound fo rm a tio n w ith TNB.

The

th io p h e n e compound i s a p p a r e n tly a weak one f o r t h e s o lv e n t can b e slo w ly rem oved b y pum ping.

The benzene compound i s s e e n t o b e q u i t e

s t a b l e f o r , a f t e r a lo n g p e r io d o f pumping, t h e r e was a v e r y sm all change i n w e ig h t a lth o u g h t h e r e was more th a n one mole o f benzene p e r mole o f TNB.

The p re se n c e o f such a l a r g e e x c e ss o f benzene

can n o t b e a c co u n ted f o r by t h e p re se n c e o f an im p u rity such as w a te r i n t h e b e n ze n e.

The benzene was d r ie d o v e r calcium h y d rid e ;

b e s id e s , t h e s o l u b i l i t y o f w a te r i n benzene i s n o t la r g e enough to acco u n t f o r t h i s g r e a t e r w e ig h t.

The ex cess w e ig h t m u st, th e r e f o r e ,

b e d u e t o b en z en e. The R e s u lts o f P ro ce d u re No. 2 .

T h is p ro c e d u re was a p p lie d

t o c a rb o n t e t r a c h l o r i d e , e t h e r , te tr a h y d r o f u r a n , to lu e n e , b en zen e, and th io p h e n e . 26.

The d a ta f o r P ro ced u re No. 2 a r e g iv en i n T ab les 21 th ro u g h

The f i r s t column i n th e s e t a b l e s

removed fro m th e f l a s k .

g iv e s t h e number o f m illim o le s

T his was c a lc u la te d from th e gas law knowing

73

Table 21 Change o f Vapor P re s s u re w ith Change i n S o lv e n t C om position o f a S o lu tio n o f TNB i n Carbon T e tr a c h lo r id e t = 21».99 t 0.0l»° M i l l i m o l e s TNB = 2 . Ola Mmoles

Removed 6 .2 3 3.8 2 3 .8 9 3.7 5 U.01 U.01 U.32 U.03 U.ltO 3 .9 6 3 .2 1 1 .8 2 1.1*9 0.3 5 5 0 .5 5 5 0 .1 3 8 0.091» 0 .2 3 6 0.2 3 9 0.361» 0.121»

M moles Rem oved C o r r e c te d

6 .2 7 3 .8 5 3 .9 2 3 .7 8 It.Ol» U.01» U.35 1».06 1».1»3 3 .9 9 3.21» 1 .8 2 1.1*9 0 .3 5 5 0 .555 0 .138 0.091» 0 .236 0.239 0.361» 0.121»

M m oles R e m a in in g

5 1 .3 8 * li5 .1 l 1*1 .2 6 37.31* 3 3 .5 6 2 9 .5 2 25.1*8 2 1 .1 3 17.07 12.61» 8.65 5.1*1 3 .5 9 2.105 1.7 5 0 1.195 1.057 0.963 0.727 0.1*88 0.121* 0

M moles i n S o ln

UU.55 1*0 .7 0 36.78 33.00 28.95 21*. 89 20.51* 1 6 . 1*8 1 2 .0 6 8 .0 8 Ü.8U 3 .0 3 1 .5 8 1.21* 0 .7 3 0 .6 1 0.5 2 0.31* 0 .2 1 0.01» 0

P r e s s , (m m .)

1 1 0 .9 110.1» 1 1 0 .6 110.7 110.1» 1 1 0 .1 109.8 109.3 108.5 107. lb 10 5 .8 ° 101». 2 97 .1 95.1» 87.1* 81*.3 81 .8 72.3 5 2 .8 11».!* 0

a.

7 , POL g . (5 1 .3 9 mmoles) o f carb o n t e t r a c h l o r i d e w ere w eighed a t t h e s t a r t . The TNB was d is s o lv e d a t 70°, b u t a c o n s id e ra b le amount had c r y s t a l l i z e d a t 25°. Volume o f f l a s k = 100 m l.

b.

No l i q u i d phase was p r e s e n t.

c.

The sum o f t h e f r a c t i o n s c o lle c te d = liU-63. t e t r a c h l o r i d e o b ta in e d b y w eighing = UU.95.

Mmoles o f carbon

7h

Table 22 Change of Vapor Pressure with Change in Solvent Composition of a Solution of TNB in Ether t = 0 .0 0 ± 0 .0 1 0 M i l l i m o l e s TNB = 1 .1 8 8

Mmoles Removed

2 5 .7 0 1 8 .U6 1 8 .1 8 1 7 .8 6 1 9 .0 9 1 8 .0 0 1 8 .2 9 1 9 .2 6 1 7 .8 8 18.17 1 9 .5 1 18 .6 5 ^ 23.62 1 9 .1 6 55.1t7 5 2 .8 8 3U.U8 3 8 .2 0 9 .5 1 I t.96 1 .4 0 0 .2 3 1 o.o46 1 .3 3 1 .6 7 1 .1 3 1 .3 0

Mmole s Removed C o r r e c te d

25 .83 1 8 .5 6 1 8 .2 8 1 7 .9 5 1 9 .1 9 1 8 .0 9 1 8 .3 8 19.36 1 7 .97 1 8 .2 6 1 9 .6 1 1 8 .75 23.75 1 9 .5 4 5 5 .7 8 53 .1 7 34 .6 2 3 8 .4 1 9 .5 6 e 4 .9 8 1 .4 0 .231 0 .0 4 6

M moles R e m a in in g

471.72& 445.89 427.33 409.05 391.10 371.91 353.82 3 35.44 3 1 6 .0 8 298.11 279.85 260 .2 4 241.49 217.74 1 98 .2 0 142.42 89.25 5 4.63 1 6 .2 2 6 .6 6 1 .6 8 0.277 0 .0 4 6 0 0.277 6 .6 6 5 .3 3 3 .6 6 2 .5 3 1 .2 3

M moles i n S o ln

445 .3 4 426.66 408.36 390.39 3 71.18 353.06 334.66 315.28 297.29 2 79.01 259.38 240.60 216.83 188.85 141.42 8 8.20 5 3 .5 3 15.09 5 .5 4 0 .6 6 0.060 0.008

P ress.

1

185.7 1 8 5 .8 1 8 6 .0 185.9 1 85.9 1 8 5 .8 1 8 5 .8 1 85.7 185.8 1 85.6 185.6 185.7 1 8 5 .5 1 8 5 .5 1 8 5 .4 185.3 1 8 4 .9 1 8 4 .8

1 8 3 .8 c 1 6 7 .1 3 5 .4 6 .2 0

0 .0 5 4 5 .5 4 4 .2 1 2.55 1 .4 4 .31

3 6 .4 d 183. 7d 183.0 1 8 1 .0 177.5 1 5 0 .8

a.

3 U -9 6 0 g . (1 :7 1 .6 6 m m o les) o f e t h e r w e r e w e ig h e d a t s t a r t . The TNB w as d i s s o l v e d a t £ 0 ° , and r e m a in e d i n s o l u t i o n a t 2 5 ° . TNB p r e c ip it a t e d a t i c e te m p e r a tu r e . V o l. o f f l a s k = 1 0 8 m l.

b.

Sum o f t h e f r a c t i o n s c o l l e c t e d = 2 2 9 . 1 . b y w e ig h in g = 2 3 0 . 3 .

c.

No l i q u i d w as p r e s e n t . Sum o f f r a c t i o n s c o l l e c t e d s i n c e l a s t w e ig h in g ■ 2 3 3 . 6 . M m oles o b t a i n e d b y w e ig h in g = 2 3 1 :.9 .

d.

E th e r w a s a d d ed t o t h e TNB.

M moles o f e t h e r o b t a in e d

75

Table 23 Change of Vapor Pressure with Change in Solvent Composition of a Solution of TNB in Tetrahydrofuran t = 25.00 ± 0 .0 3 0 Mmoles TNB = 2.0U9 Mmoles Removed lw 137 2.787 3.137 In 926 In 087 In 21*3 U. 2 86 1n 371 1n 39U U.391 3 .1 0 1 3 .536 3 .835 2 .763 2.667 2.006 1 .526 0.39k 0 .221 0.5k7

Mmoles Removed C o rre c te d In 11 2.7 7 3 .1 2 In 90 In 07 It. 22 In 26 It.36 It. 37 It.37 3 .0 8 3 .5 2 3 .8 1 2 .7 5 2 .6 5 2 .0 0 1 .5 2 0 .3 9 0.2 2 0.5U

Mmoles Rem aining

Mmoles i n S o ln

61.03% 5 6 .9 2 5k . 15 5 1 .0 3 k 6 .l3 k2.06 37.8k 33.58 29.22 2k. 85 2 0 .k8 1 7 .k0 1 3 .8 8 10.07 7 .3 2 k .67 2.67 1 .1 5 0 .7 6 o .5 k 0 1 .5 0 2 .1 6 2.67

56 .1 8 5 3 .3 1 5 0 .2 0 k 5.30 k l.2 3 37.02 32.77 2 8 .k l 2k. 05 1 9 .7 0 16.63 1 3 .1 3 9.27 6 .5 3 3 .9 0 1 .9 5 0 .6 1 0 .3 5 0 .2 2 0 0.86 l.k 7 1 .9 5

P r e s s , (mm.) 1 5 6 .6 1 5 6 .1 155.7 1 5 5 .0 I5 k .3 153.6 152.3 1 51.1 lk 9 .2 lk 6 .2 lk 3 .k b lk o .6 lk 9 .5 c lk 7 .3 lk 3 .7 133.5 1 0 0 .1 7 7 .6 6 0 .1 0 1 20.68 1 2 9 .5d I 3 k .l d

a.

U.3938 g . ( 6 0 . 9U mmoles) o f te tr a h y d r o f u r a n w ere w eighed a t t h e s t a r t . The TNB d is s o lv e d a t 2 8 °. Volume o f f l a s k - 100 m l.

b.

S o lid f i r s t ap p eared a t t h i s p o in t

c.

d.

No l i q u i d phase was p r e s e n t . The sum o f th e f r a c t i o n s c o lle c te d = 51*23. Mmoles o f te tr a h y d r o f u r a n o b ta in e d by w eighing = 5 0 .9 5 . T his re a d in g was o b ta in e d a f t e r 10 h o u rs t h e f i r s t r e a d in g was 13U mm. T e tra h y d ro fu ra n was added to t h e TNB.

76

T a b le 2h Change o f Vapor P r e s s u re w ith Change i n S o lv e n t C om position o f a S o lu tio n o f TNB i n T oluene t = 25.07 ± 0 . 0l*o M illim o le s TNB = 2.01*0 Mmoles Removed 3.3U 1 .2 7 2 .7 2 2 .7 6 U.78 2.7U 8 .3 0 8.2 7 5 .2 0 2 .6 8 5.1*7 8.1*5 8.6 3 8.3 8 8.2 5 8 .0 0 5 .3 3 5 .5 3 5 .0 8 2.61* 1 .1 5 0.61*5 0.361* 0.113 0 .0 6 3

Mmoles Removed C o rre c te d 3 .3 7 1 .2 8 2 .7 5 2 .7 8 It. 83 2 .7 7 8 .3 8 8 .3 5 5 .2 5 b 2 .7 1 5 .5 2 8.51* 8 .7 2 8.1*6 8.3 3 8 .0 8 5 .3 8 5.59= 5 .1 3 2 .6 6 1 .1 6 0.6 5 0.3 6 0 .1 1 0 .0 6

Mmoles Rem aining

Mmoles i n S oln

111.19» 107.82 106.58 103.83 101.05 96.22 93.1*5 85.07 7 6 .7 2 71.1*7 6 8 ,7 6 63.21* 5U.70 1*5.98 37.52 2 9 .1 9 2 1 .1 1 15.73 10.11* 5 .0 1 2.3 5 1 .1 9 0.51* 0 .1 7 0 .0 6 0

107.72 106.1*1* 103.69 100.91 9 6 .0 9 93.32 81*. 91* 7 6 .5 9 7 1.33 68.62 63 .1 0 51*. 56 1*5.81* 3 7 .3 8 29.05 20.97 1 5 .5 9 1 0 .0 0 It. 87 2 .2 1 1 .0 6 0.1*2 0 .1 1 0.01*

P re ss. 1 2 9 .1 2 8 .9 2 8 .5 28.3 2 8 .1 2 8 .0 2 7 .8 2 7 .6 27.1* 27.1* 27.1* 2 7 .3 2 7 .2 2 7 .2 2 7 .2 27.1* 27.2 2 6 .6 25.9 2l*.3 2 1 .8 1 1 .9 lt.2

a.

10.2515 g . (1 1 1 .2 7 mmoles) o f to lu e n e was w eighed a t s t a r t . The TNB d is s o lv e d slo w ly a t 2 7 °. Volume o f sy stem = 97 m l.

b.

S o lid f i r s t ap p eared a t t h i s p o i n t .

c.

No l i q u i d p h ase was p r e s e n t a t 1 2 .8 mmoles. The sum of t h e . f r a c t i o n s c o l l e c t e d = 1 0 0 .1 . Mmoles o f to lu e n e o b ta in e d b y w eig h in g = 1 0 1 .1 2 .

77

T able 25 Change of Vapor Pressure with Change in Solvent Composition of a Solution of TNB in Benzene t = 25.OU - 0.030 Millimoles of TNB = 2.01*1 Mmoles Removed 2 .7 5 2 .6 9 5 .3 k 7 .8 k 8.2 7 23.65 8.56 8.9 9 8 .9 k 8 .9 5 8 .9 6 8 .8 3 9 .1 8 8 .2 8 2.k 8 0 .8 9 0 .5 1 0 .1 5 1 0.127 R etu rn ed R etu rn ed 2 .5 1

Mmoles Removed C o rre c te d 2 .7 6 2.6 9 5 .3 6 7 .8 7 8 .3 0 23.73 8 .5 9 9 .0 2 8.9 7 8 .9 8 8 .9 9 8 .8 6 9 .2 1 8.3 1 2.kB 0 .8 9 0 .5 1 0.151 0.127 0.127 0 .1 5 1

Mmoles Rem aining

Mmoles i n S oln

P re ss. 1

12 8 .0 3 a 125.27 122.58 1 17.22 109.35 1 01.05 77.32 68.73 5 9 .7 1 5 0 .7 k k l .7 6 32.77 23.91 lk .7 0 6 .3 9 3 .9 1 3 .0 2 2 .5 1 2.3 6 2.2 3 2 .3 6 2 .5 1 0

12k.76 122.07 116.71 108 .8 k 1 0 0 .5 k 76.82 6 8 .2 3 5 9 .2 1 5 0 .2 k k l.2 6 3 2 .2 7 23.kL l k .2 0 5 .8 9 3 .k 3 2 .5 9 2 .2 6 2 .2 2 2.2 0 2.2 2 2.2 6

9 6 .2 9 6 .0 9 5 .k 95.1 9k.5b 9 k .0 9 3 .7 9 3 .6 93.7 93.7 93.7 9 3 .8 93.7 92.6= 89.7 80.7 k2 .5 23.5 6 .6 2 6 .0 8 k 6 .2 d

a.

10.0006 g . (1 2 8 .0 3 mmoles) o f b en zen e w ere w eighed a t s t a r t . The TNB was d is s o lv e d a t 7 0 °. A sm a ll amount o f TNB p r e c i p i t a t e d a t 2 5 °. Volume o f sy stem = 100 m l.

b.

The v a p o r p r e s s u r e o f t h e benzene c o lle c te d t o t h i s p o in t was 9 7 .3 mm. a t 2 5 .0 3 ° . The v a p o r p r e s s u r e o f t h e p o r tio n s c o lle c te d a f te rw a r d s was 9 5 .0 mm. a t 2 5 .0 5 °.

c.

Sum o f f r a c t i o n s c o l l e c t e d - 1 2 1 .2 2 . Mmoles of ben zen e o b ta in e d by w eig h in g - 121.61*. No l i q u i d p h ase was p r e s e n t.

d.

These p o r tio n s w ere r e tu r n e d t o f l a s k i n o rd e r t o check e q u ilib riu m c o n d itio n s .

78

Table 26 Change of Vapor Pressure with Change in Solvent Composition of a Solution of TNB in Thiophene t = 2lw90 ± 0.07° milirnoles TNB = 2.008 Mmoles Removed

Mmoles Removed C o rre c te d

3 .2 7 1*93 2 .2 6 2.U0 2.7 2 5 .0 2 6.99 6 .8 1 6 .7 7 6 . où 6.U9

12.78b 5 .3 3 ° 2.3U 2 .328 3.9Ù U.08 2 .8 6 1.U2 1 .5 1 0 .5 3 1 0 .2 8 2 0.1 8 1 0.238 0.1 0 0 0 .1 0 k 1.2U2

3 .2 6 1 .9 1 2.2 5 2 .3 9 2 .7 0 5 .0 1 6 .9 7 6 .7 9 6 .7 k 6 .0 2 6 .k 6 0.1 5 1 2 .7 3 5 .3 2 2 .3 3 2.3 2 3 .9 2 k .0 7 2 .8 k l.k l 1 .5 1 0 .5 3 0 .2 8 0 .1 8 0 .2 k 0 .1 0 0 .1 0 1 .2 k

Mmoles Rem aining 89.79* 86.53 8k .62 82.37 7 9 .9 8 77.28 72.27 6 5 .3 0 5 8 .5 1 5 1 .7 7 k5.75 3 9 .2 9 3 9 .1 k 2 6 .k l 2 1 .0 9 1 8 .7 6 1 6 .kk 1 2 .5 2 B.k5 5 .6 2 k .2 0 2 .6 9 2 .1 6 1 .8 6 1 .6 8 l.k k l.3 k l.2 k 0

Mmoles i n S o ln

P r e s s , (m i. )

86.11 8 k .20 81.95 79.57 76.87 7 1 .8 6 6 k . 89 5 8 .1 0 5 1 .3 6 k 5 .3 5 3 8 .8 9

7 7 .6 7 7 .5 7 7 .5 7 7 .3 7 7 .1 7 7 .0 76 .7 76 .5 7 6 .1 7 5 .6 7 k .9

26.02 20.69 18.37 1 6 .0 5 12.13 8.07 5 .2 6 3 .8 8 2.k5 1 .9 8 1 .7 3 1 .6 1

7 3 .k 7 3 .6 7 3 .k 7 2 .9 7 1 .8 7 0 .1 6 5 .k 5 9 .8 k k .5 3 2 .6 2 3 .6 16.88 8 .6 8 .2 6 .9 *

l.k o 1 .3 1 1.21

a.

7*5510 g. (8 9 .7 5 mmoles) o f th io p h e n e was w eighed a t s t a r t . TNB d is s o lv e d a t 2 8 °. V o l. o f sy stem = 105 m l.

b.

Sum o f f r a c t i o n s c o l l e c te d th ro u g h h e re = 63.1^8. th io p h e n e o b ta in e d by w eighing = 6 3 .2 2 .

c.

A la r g e amount o f s o l i d p r e c i p i t a t e d a t t h i s p o in t.

d.

Sum o f f r a c t i o n s c o l l e c t e d s in c e p r e v io u s w eig h in g = 2 6 .U7• Mmoles o f th io p h e n e o b ta in e d b y w eig h in g - 2 6 .3 8 .

d. e.

No l i q u i d p h ase was p r e s e n t a t 16.05 mmoles. 12 h o u rs.

f .

8 h o u rs.

iîraoles o f

The

79

t h e volume o f t h e vacuum l i n e o ccu p ied b y t h e g a s , th e p r e s s u r e o f th e gas and t h e room te m p e r a tu re .

The second column g iv e s t h e c o r r e c te d

number of m illim o le s rem oved.

A f te r some o f th e removed s o lv e n t had

accu m u lated gave a

i t was removed from t h e vacuum l i n e

more a c c u r a te v a lu e

o f t h e number

was ta k e n a s t h e " tr u e " v a l u e .

and w eighed. T h is

o f m illim o le s removed and

The d i f f e r e n c e betw een th e " tr u e "

v a lu e and t h e sum o f t h e number o f m illim o le s removed was d iv id e d by t h e " tr u e " v a l u e .

T h is gave th e c o r r e c t i o n t o be a p p lie d to

each m illim o le o f column 1 . i n column 2 .

The c o r r e c te d re a d in g s were th e n re c o rd e d

The m illim o le s rem ain in g i n th e f l a s k , re c o rd e d i n

column 3 , was o b ta in e d b y s u b tr a c t in g th e t o t a l number o f m illim o le s removed from t h e o r i g i n a l number o f m illim o le s . The v a lu e s o f column 3 had t o b e c o r r e c te d f o r th e f r e e sp ace i n th e sy stem . A.

^

s P

w here

nc P v 299

The fo llo w in g e q u a tio n was used tS o

*

^

3 5 .3 6 X

frr.

= m illim o le c o r r e c tio n t o be s u b tr a c te d » p r e s s u r e g iv en i n column 5 = volume o f t h e f l a s k l e s s th e volume - room te m p e r a tu re .

of s o lu ti o n

The c o r r e c t i o n f o r t h e e th e r s o lu tio n , w hich was ru n a t ic e te m p e ra tu re , was made u s in g th e f o llo w in g e q u a tio n s , ifhen no s o l u t i o n was p r e s e n t : B.

n c ” 22 TUT

\jÉs 4

x H i] - °-00612 ?"

"When s o lu t i o n was p r e s e n t:

nc=

E65- vs ) x

= [(65-va ) 0 . 2a

* 185.5 + 9 .59]

x

22711

^

x

2 7 |J

1

80

but

v s = O.lOii (n e- n c )

hence «nc — =

C, w here

n

c

V l / ^ r f_ n m l . / « e- n « c \)]1 n0.2UU o). 1. + . n j j65-0.10tt(n

cfo I ^ 9.5?]

= 1 .1 6 5 - 0.00116 n e G

65 U3 Vg ne O.lOU 1 8 5 .5

= volume o f f l a s k a t 0° - volume of system a t 26° = volume of s o lu tio n ■t o t a l number o f m illim o le s o f e th e r i n th e system = volume o f one m illim o le o f e t h e r = a v era g e o f 18U.9 and 186. 0 , th e p r e s s u r e ra n g e t o w hich t h i s e q u a tio n was a p p lie d .

E q u a tio n B was u se d when no l i q u i d p h ase was p r e s e n t i n th e f l a s k , w h ile C was used when s o lu t i o n was p r e s e n t .

Column b g iv e s o n ly

th e amount of s o lv e n t p r e s e n t i n s o lu tio n o r i n th e s o l i d p h a se . The l a s t column r e c o rd s th e p r e s s u r e i n m illim e te r s o f m ercury c o r r e c te d to z e ro d e g re e s c e n tig r a d e .

The p r e s s u r e was n o t c o r r e c te d

f o r a c c e l e r a t i o n due t o g r a v i ty , f o r t h e c o r r e c ti o n was o n ly a b o u t 1 p a r t i n 2000. I n m ost case s an e q u ilib riu m p re s s u re was re a c h e d i n n o t more th a n one hour a f t e r t h e gas was removed from th e sy stem . some c a s e s e q u ilib riu m was slo w ly e s ta b lis h e d .

However, i n

For th e s e th e number

o f h o u rs from t h e rem oval o f t h e v ap o rs t o th e f i n a l p r e s s u r e re a d in g was g iv e n as a f o o tn o t e t o th e t a b l e . I n o rd e r t o g e t a l l of th e graphs o f th e d a ta on one s h e e t f o r com parison, t h e q u a n tity “v ap o r p r e s s u r e o f t h e s o lu tio n d iv id e d by t h e v ap o r p r e s s u r e o f t h e s a tu r a te d s o l u t i o n ” was p l o t t e d as o r d in a te .

The m illim o le s o f s o lv e n t i n s o lu t i o n was p l o t t e d as

a b s c is s a .

T h is i s shown i n F ig u re 1 2 .

Curve I shows th e b e h a v io r

o

in

Nonm os ggivwnivs

O 10

aynssawa

M 3 1 S A S JO 3 tin S S 3 tid

82

e x p e c t e d i n "th e c a s e o f com pound f o r m a t io n . o b t a in e d fr o m t h e b e n z e n e d a t a .

C urve I I I "was t h a t

I f t h e d a ta on th e d is s o c ia t io n

p r e s s u r e s f o r T N B -b en zen e fr o m C h a p te r I I I a r e i n c l u d e d , i t i s s e e n t h a t t h e g e n e r a l s h a p e o f C urve I I I w o u ld b e t h e sam e a s t h a t o f C urve I ; t h a t i s ,

a h o r i z o n t a l w o u ld b e p r e s e n t a t a l o w e r p r e s s u r e ,

n a m e ly a t a b o u t 26 nm. t h io p h e n e d a ta »

Curve IV g i v e s t h e g r a p h o b t a in e d fro m t h e

The c u r v e i s

one m illim o le o f s o lv e n t .

s e e n t o t e r m in a t e a t som ew hat m ore th a n

T h is i s

p r o b a b ly due t o l a c k o f e q u i li b r iu m

d a t a , an d th e r e s u l t s c a n b e i n t e r p r e t e d a s i n d i c a t i n g t h e f o r m a t io n o f a w eak com pound. C urve I I g i v e s t h e s h a p e o b t a in e d f o r t h e d a t a o f c a r b o n t e t r a c h l o r i d e , t o l u e n e , e t h e r , an d t e t r a h y d r o f u r a n s o l u t i o n s (th e d a ta p l o t t e d a r e t h o s e f o r carb on t e t r a c h lo r i d e , b u t th e o th e r d a ta f o llo w t h i s cu rv e c lo s e ly ;

t e t r a h y d r o f u r a n , h o w e v e r , sh ow ed

a minimum d u e t o s u p e r s a t u r a t i o n ) . f o r m a t io n o n e w o u ld e x p e c t t o

I n t h e c a s e o f no compound

o b ta in a h o r iz o n t a l l i n e a s r e p r e s e n te d

b y t h e e x t e n s i o n o f t h e u p p er l i n e o f C urve I t o t h e a x i s o f o r d i n a t e s . C urve I I ,

h o w e v e r , d e v i a t e s m a r k e d ly fr o m t h i s b e h a v i o r .

The f a c t

t h a t C urve I I d r o p s v e i y c l o s e t o t h e o r d i n a t e a x i s and t e r m i n a t e s a t th e o r ig in i s f o r m a t io n .

a g o o d i n d i c a t i o n t h a t t h e r e i s no compound

Two p h en om en a, a d s o r p t i o n o f t h e s o l v e n t b y t h e TNB

and s o l u t i o n o f t h e s o l v e n t i n s o l i d TNB, w e r e c o n s id e r e d a s e x p l a n a t i o n fo r th e d a ta .

C a l c u l a t i o n s u s i n g t h e n n il t i m o l e c u la r a d s o r p t io n

e q u a t io n ( 8 ) i n d i c a t e d t h a t t h i s a p p l i e d t o c a r b o n t e t r a c h l o r i d e . The d a t a , h o w e v e r , h ad t o b e d i v i d e d i n t o tw o r e g i o n s i n o r d e r t o f i t t h e e q u a tio n .

The o t h e r s o l v e n t s sh ow ed l i t t l e

c o n f o r m it y

83

t o t h i s e q u a tio n .

The phenom enon o f a s o l u t i o n o f t h e s o l v e n t i n

t h e TNB se em s t o b e m ore r e a s o n a b l e . I n e v e r y e x p e r im e n t t h e m i l l i m o l e s o f s o l v e n t p r e s e n t "where l i q u i d p h a s e c o u ld n o l o n g e r b e s e e n w as a t l e a s t t h r e e t i m e s g r e a t e r th a n t h e m i l l i m o l e s o f TNB.

The c o m p o s it io n a t t h i s

p o in t v a r ie d

fr o m 6 t o 1 6 m i l l i m o l e s o f s o l v e n t f o r tw o m i l l i m o l e s o f TNB.

T h is

l a r g e am ount o f s o l v e n t p r o b a b ly w a s d i s s o l v e d i n t h e s o l i d TNB.

A

s o l u t i o n phenom enon w o u ld a c c o u n t f o r t h e b e h a v io r o f C u rve I I fr o m t h e p o i n t w h e r e no l i q u i d p h a s e w a s p r e s e n t t o n o s o l v e n t w as p r e s e n t .

t h e o r i g i n , w h ere

I t w ou ld a l s o a c c o u n t f o r t h e b e h a v io r o f

C u rves I I I and IV i n t h e r e g i o n w h e r e o n l y s o l i d w a s p r e s e n t . th e se c a s e s th e s o lv e n t i s

In

a p p a r e n t ly s o l u b l e i n t h e T N B -s o lv e n t

com pound.

D is c u s s io n . a g reem en t.

The r e s u l t s o f P r o c e d u r e s N o. 1 an d 2 a r e i n

B o th sh ow d e f i n i t e compound f o r m a t io n f o r TNB w i t h

b e n z e n e and b o t h sh ow t h e p r e s e n c e o f m ore t h a n o n e m o le o f b e n z e n e p e r m o le o f TNB.

H ow ever, t h e d i s s o c i a t i o n p r e s s u r e m ea su r e m en ts

o f C h a p te r I I I , and t h e e x p l a n a t i o n t h a t t h e

s o l u t i o n phenom enon

g a v e r i s e t o t h e t y p e o f C u rv es i n F ig u r e 1 2 c a n e x p l a i n t h i s

excess.

The T N B -b en zen e o b t a in e d b y r e c i y s t a l l i z i n g TNB from b e n z e n e s o l u t i o n g a v e a p r e s s u r e o f 38 mm., b u t t h e c o n t i n u a l r e m o v a l o f b e n z e n e fro m t h i s p r o d u c t r e s u l t e d i n p r e s s u r e s o f a b o u t 26 mm.

T he

sh a r p d r o p i n p r e s s u r e f o l l o w e d b y a c o n s t a n t p r e s s u r e r e g i o n m eans t h a t t h e o r i g i n a l TNB had an e x c e s s o f b e n z e n e f o r a o n e t o on e r a t i o . T he r e m o v a l o f t h i s e x c e s s g a v e r i s e t o

th e drop i n p r e s s u r e w h erea s

81+

f u r t h e r r e m o v a l o f b e n z e n e o n l y l i b e r a t e d TNB w h ic h w as n o t m i s c i b l e w ith th e s o lv a te *

The p r e s e n t e x p e r im e n t s sh o w t h a t t h i s

b e n z e n e w as i n s o l u t i o n w i t h t h e o n e t o o n e com pound.

excess

F u r th e r m o r e ,

t h e d a t a d e f i n i t e l y sh o w t h a t t h e r e w as no s o l v a t e w i t h tw o m o le s o f benzene. The tw o p r o c e d u r e s a l s o a g r e e i n s h o w in g t h a t a w eak compound w as fo rm ed b e tw e e n TNB and t h i o p h e n e , an d t h a t no compound w a s fo rm e d b e tw e e n TNB an d c a r b o n t e t r a c h l o r i d e , e t h e r , t e t r a h y d r o f u r a n , o r to lu e n e .

The o n l y d a t a o n f u r an w a s fro m P r o c e d u r e N o. 1 w h ic h show ed

n o compound f o n n a t i o n . E xam in atL on o f t h e d a t a r e v e a l s t h e f o l l o w i n g s t r i k i n g r e l a t i o n ­ s h ip s .

T o lu e n e d o e s n o t fo r m a compound w h e r e a s b e n z e n e d o e s .

b e n z e n e compound i s tu r n i s

The

more s t a b l e th a n t h a t w i t h t h io p h e n e w h ic h i n

m ore s t a b l e th a n t h a t w i t h f u r an (w h ic h d o e s n o t a p p e a r t o

fo rm a com p ou n d ).

The l a c k o f com pound f o r m a t io n w i t h t o l u e n e may

b e a t t r i b u t e d t o t h e g r e a t e r l e n g t h , an d p e r h a p s g r e a t e r t h i c k n e s s , o f t h i s m o le c u l e a s com p ared w i t h b e n z e n e .

The p r e s e a c e o f a

c o o r d in a t i n g a to m i n , an d t h e s m a l l e r s i z e o f t h io p h e n e th a n b e n z e n e w o u ld b e e x p e c t e d t o f a v o r compound f o r m a t i o n . o f t h e t h io p h e n e compound i s

The l o w e r s t a b i l i t y

s u r p r i s i n g w h en t h e s e f a c t o r s a r e c o n s i d e r e d .

H o w ev er, t h e l a c k o f com pound f o r m a t io n w i t h f u r a n s u g g e s t s t h a t t h e p r e s e n c e o f su c h a c o o r d i n a t i n g atom m^r b e u n im p o r ta n t i n l e a d i n g t o com pound f o r m a t i o n .

The d e c r e a s e i n s t a b i l i t y o f t h e

c r y s ta llin e

com pounds i n t h e o r d e r b e n z e n e , t h i o p h e i e , a n d f u r an f o l l o w s t h e d e c r e a s e i n t h e s i z e o f t h e s e m o le c u le s . s ta b ility

T h is s u g g e s t s t h a t t h e

o f t h e s o l v a t e d e p e n d s o n t h e p r e s e n c e o f a s o l v e n t m o le c u l e

85-

o f j u s t t h e r i ^ i t s i z e t o p e r m it a maximum f i l l i n g o f s p a c e i n t h e c r y s t a l l e a d i n g t o a minimum p o t e n t i a l e n e r g y . t h io p h e n e i s a l i t t l e r ig h t ,t o

T o lu e n e i s t o o l a r g e ,

s m a l l , f u r an i s to o s m a l l , b u t b e n z e n e i s j u s t

a l l o w f o r a maximum f i l l i n g

o f sp ace.

I t w a s n o t s u r p r i s i n g t h a t a b u lk y m o le c u le l i k e t e t r a c h l o r i d e d i d n o t fo rm a com pound.

c a rb o n

The f o r m a t io n o f n o c r y s t a l l i n e

compound w i t h t e t r a h y d r o f u r a n w as n o t s u r p r i s i n g w h en c o m p a r iso n w as made w i t h f u r a n .

H ow ever, i t

w as r a t h e r s t r i k i n g t h a t t h e o n ly

com pounds fo r m e d w e r e w i t h t h e r a t h e r " f l a t " may b e o f i n t e r e s t t o f o r m a t io n .

a r o m a t ic com p ounds.

It

ex a m in e t h e e f f e c t o f t h i c k n e s s on compound

T h is c o u l d b e d o n e b y c o m p a rin g c y c l o h e x e n e , c y c l o h e x a d i e n e ,

and b e n z e n e i n a b i l i t y t o fo r m s o l v a t e s . f o r m a t io n w i t h e t h e r i s p r o b a b ly d u e t o

The l a c k o f compound i t s l e n g t h , w h ic h i s

co m p a ra b le

t o t h a t o f t o l u e n e , an d p e r h a p s i t s t h i c k n e s s .

The B e h a v io r o f t h e R e s i d u a l TNB to w a r d s 5 0 H o le P er C en t Ammonia. I n t h r e e c a s e s t h e TNB t h a t r e m a in e d a f t e r r e m o v a l o f t h e s o l v e n t w as t r e a t e d w i t h 5 0 m o le p e r c e n t am monia a t 80 ° (by t h e p r o c e d u r e g i v e n i n C h a p te r I I I ) .

T h is w a s d o n e w i t h t h e TNB fro m t h e c a r b o n

t e t r a c h l o r i d e , t e t r a h y d r o f u r a n , and t o l u e n e s o l u t i o n s . a r e g i v e n i n T a b le 2 7 .

The r e s u l t s

C om p arison o f t h e s e r e s u l t s w i t h t h a t f o r

h e a t - t r e a t e d TNB ( T a b le 1 7 ) sh ow s t h a t t h e r a t e o f p r e s s u r e d e c r e a s e w as m uch l e s s i n in p o r o s ity .

th e p r e se n t c a se .

T h is w a s p r o b a b ly due t o a d i f f e r e n c e

The TNB o b t a in e d fro m t h e p r e s e n t t r e a t m e n t w as p r o b a b ly

much l e s s p o r o u s th a n t h a t o b t a in e d b y d r i v i n g o f f b e n z e n e fr o m t h e T N B -b en zen e com pound.

86

Table 27 B e h a v io r o f TNB O b ta in e d fr o m V a r io u s S o l v e n t s ■with SO M ole P e r C e n t Ammonia t ™ 80°

A*

TMB fr o m C arbon T e t r a c l i l o r i d e 3

S

9

70

6 0 .5

5 3 .5

Tim e (m in . ) P r e s s , (m m .)

B.

P r e s s , (m m .)

68

U i .2

3 7 .1

31*8

3 1:1.9

U

6

8

U 6 .9

5 0 .7

5 1 .5

11

15

5 l* 5

5 0 .9

30 1:9.2

U

U8

U .5

U i*

TNB fr o m T o lu e n e

Tim e ( m i n .) P r e s s , (m m .)

*

35

TNB fr o m T e t r a b y d r o fu r a n

Tim e (m in . )

C.

16

2

k

8

675 U .6

U 7 .0

16 lO-.O

32

60

3 5 .1

3 1 .9

R e a d in g w as m ade w i t h d r y i c e b a t h a t c e n t e r t u b e .

90

130

2 9 .7 2 7 .5

132

25*

87

T h e S o l u b i l i t i e s o f TNB

The S o l u b i l i t y o f TNB i n V a r io u s S o lv e n b s fr o m D a ta o f P r o c e d u r e N o. 2 .

The d a t a i n T a b le s 21 t h r o u g h 26 w e r e u s e d t o

s o l u b i l i t y o f TNB i n t h e s o l v e n t s u s e d . b y tw o m e t h o d s .

c a lc u la te th e

T he s o l u b i l i t i e s w e r e o b t a in e d

O ne, b y a p p ly in g R a o u l t 1s la w u s i n g t h e p r e s s u r e o v e r

th e sa tu r a te d s o lu tio n ;

t w o , fr o m t h e m o le f r a c t i o n w h er e t h e l i n e f o r

u n s a t u r a t e d s o l u t i o n m e e ts t h e l i n e f o r s a t u r a t e d a d d i t i o n a majrimum v a l u e o f t h e s o l u b i l i t y e t h e r and b e n z e n e s o l u t i o n s .

s o lu tio n .

In

c o u ld b e o b t a in e d f o r t h e

I n t h e s e tw o c a s e s a s m a l l am ount o f

s o l i d w a s p r e s e n t a t t h e s t a r t o f t h e e x p e r im e n t , and t h e maximum v a l u e f o r t h e s o l u b i l i t y w a s o b t a in e d b y u s i n g t h e w e i g h t s o f t h e o r ig in a l m a te r ia ls . R a o u l t 1s la w c a n b e e x p r e s s e d m a t h e m a t ic a lly b y

w here

= ( i n t h i s c a s e ) v a p o r p r e s s u r e o f t h e s a tu r a t e d Pq - v a p o r p r e s s u r e o f t h e p u re s o lv e n t, and N]_ - mole f r a c t i o n o f s o lv e n t.

s o lu t i o n ,

N]_ can b e c a l c u l a t e d fro m t h e o b serv ed p r e s s u r e f o r th e s a tu r a te d s o l u t i o n a n d fr o m t h e v a p o r p r e s s u r e o f t h e s o l v e n t .

One c a n now

c a l c u l a t e t h e m o le f r a c t i o n o f TNB, N g, s i n c e

Ng — 1 — Nq_• A ls o

and

Ng x 3 9 2 .3 -

gram s o f TNB,

x Wg - gram s o f s o l v e n t , w h er e Ws - m o le w e i g h t o f th e an d 3 9 2 .3 = m o le w e i g h t o f TNB.

s o lv e n t

88

I f X i s t h e s o l u b i l i t y i n grams o f TNB p e r 100 grams of s o l u t i o n , th e n X 100 - X

hence

X =

N? x 3 9 2 .3 N-i x W^ 5 9 100 x 392.3 x Mg 3 9 2 .3N2 t Ki x Ws

E

T a b le 28 g i v e s t h e s o l u b i l i t y a s c a l c u l a t e d b y t h i s e q u a t io n ( E ) . T a b le 2 9 g i v e s t h e

s o lu b ilitie s

as c a l c u l a t e d fr o m t h e i n t e r c e p t

o f t h e l i n e s f o r u n s a t u r a t e d and s a t u r a t e d

s o l u t i o n s when t h e v a p o r

p r e s s u r e w as p l o t t e d a g a i n s t m i l l i m o e s o f s o l v e n t .

The number o f

m i l l i m o l e s o f s o l v e n t r e a d fro m t h e g r a p h and t h e p r o b a b le e r r o r i n t h is v a lu e i s

g iv e n i n co lu m n 3*

The s o l u b i l i t y w a s t h e n c a l c u l a t e d

b y f o r m u la F . W+ x 1 0 0

F.

ms x Ws / 1000 V %

“ g * TNB P 6 r 100 g *

s °:L"u:b:LOn^

w here

= w e ig h t o f TNB o r i g i n a l l y w e i g h e d o u t, Wg = m ole w t. o f s o lv e n t, and mg = m illim o le s o f s o lv e n t i n s o lu t i o n . The am ount o f s o l i d p r e s e n t a t t h e s t a r t o f t h e m ea su r e m en ts

i n t h e b en zen e and e th e r s o lu tio n s was s m a ll. w e r e p r e s e n t w i t h 0 .8 0 0 5 g .

o f TNB.

a s 7 .U g . p e r 1 0 0 g . o f s o l u t i o n . w i t h 0 .U 6 6 g .

o f TNB.

T h is g i v e s

p e r 100 g . o f s o l u t i o n .

T h is g i v e s t h e maximum s o l u b i l i t y F or e t h e r 3U*96 g . w e r e p r e s e n t

t h e maximums o l u b i l i t y

These v a lu e s w ere ta k e n

when e v a lu a tin g t h e s o l u b i l i t y d a t a . s o lu b ilit y d a ta . d e s ir e d , i t

For b enzene 1 0 .0 g .

as 1 .3 g .

in to c o n s id e r a tio n

T ab le 30 g iv e s t h e e v a lu a te d

A lth o u g h t h e s o l u b i l i t y r e s u l t s l e a v e much t o b e

i s b e l i e v e d t h a t t h i s m eth o d w i l l g i v e b e t t e r r e s u l t s

i n m ore f a v o r a b l e c a s e s .



1A

CM H

CM

ho

M i •) 0) W PL,Ch o

-d "

c—

XA

NO

INNO

00

H CM

NO

-d 1—1

1—1

NO

O

NO

On

8

co

OC^-

CO

CA c—

ININ-

s

NO

co

0

CA

1

-p

0)

O'N

TO