The reaction of trimethylamine with some inorganic acid chlorides

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THE REACTION OF TRIMETHYLMINE WITH SOME INORGANIC ACID CHLORIDES

A T h e sis P resen ted to t h e F a c u l t y o f t h e D e p a rtm en t o f C h e m is t r y U n iv e r s it y o f S ou thern C a lif o r n ia

In P a r tia l F u lfillm e n t o f t h e R e q u ir e m e n ts f o r t h e D e g r e e M aster o f S c ie n c e

by J o s e p h Umlah M e s s e n g e r June 1942

UMI Number: EP69774

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UMT D is se rta tio n P u b lish in g

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This thesis, w ritten by l Q S E 2 R M i l ^ . J $ & 5S R m E R ..........................

under the direction of h.. is Faculty Committee, a n d a p p r o v e d by a l l its m e m b e r s , has been presented to and accepted by the Council on Graduate Stu dy and Research in partial fulfill­ m e n t of th e r e q u i r e m e n t s f o r the d e g r e e of

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Secretary

r,„„ J u n e , 1 9 4 2

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Chairman

TABLE OF CONTENTS CHAPTER I.

PACE

THE PROBLEM AND D E F I N I T I O N ..........................

1

D e fin itio n s

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

1

The p r o b le m

. . . . .

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

2

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

2

E a r l i e r work

S t a t e m e n t o f t h e p r o b le m

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

Im p o r ta n c e o f t h e s t u d y ........................ Mode o f a t t a c k II.

IV .

3

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

REVIEW OF THE LITERATURE

3

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

F e a s i b i l i t y o f t h e p r o b le m III.

2

4

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

REAGENTS PREPARED AND P U R IF IE D .....................

5 7

Trim e t h y l a m i n e ............................................

7

C arbon t e t r a c h l o r i d e and c h l o r o f o r m . . .

7

E t h e r ..........................................................................

7

A r se n ic t r i c h l o r i d e

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

7

B ism u th t r i c h l o r i d e

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

9

TECHNIQUE AND RESULTS OF INDIVIDUAL EXPERIMENTS.................................................

11

T e c h n iq u e

11

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

A n a l y t i c a l m e t h o d ............................................

12

A r s e n i c t r i c h l o r i d e and t r i m e t h y l a m i n e . .

13

A n tim on y t r i c h l o r i d e and t r i m e t h y l amine

.

15

. .

15

B ism u th t r i c h l o r i d e and t r i m e t h y l a m i n e

iii CHAPTER 7.

PAGE

STABILITY OF THE ADDITION COMPLEXES..................... S t a b i l i t y by a n a l y s i s

20

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

20

S t a b i l i t y by d e c o m p o s i t i o n .........................................

20

I o n i c t e n d e n c i e s , a s r e c o g n i z e d by t h e c o n d u c t i v i t i e s o f t h e c o m p le x e s d i s s o l v e d in liq u id s u lfu r d io x id e 71.

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

CONCLUSIONS AND PROBLEMS FORFUTURE STUDY

. .

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

25 30 32 35

LIST OF TAELIS TABLE I. II. III. IT . T.

PAGE B a t a E s t a b l i s h i n g F orm u lae o f C o m p lexes D e c o m p o s i t io n o f AsC1 3 *3N(CH3 ) 3

. . .

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

16

21

D e c o m p o s i t io n o f 2BiClg*3N(CHg) g . . . . . . .

22

C o n d u c t i v i t i e s i n L i q u id S u l f u r D i o x i d e

26

C o n d u c t i v i t i e s i n W a t e r ..........................

. . .

27

LIST OF FIGURE FIGURE 1.

PAGE A p p a r a tu s f o r t h e P u r i f i c a t i o n

o f A rsen ic.

T r i c h l o r i d e ...............................................................................

Zm

A p p a r a tu s f o r t h e P u r i f i c a t i o n

of

B ism u th

T r i c h l o r i d e ............................. 3.

10

A p p a r a tu s f o r e x t r a c t i o n w i t h L i q u i d S u l f u r B i o x i d e .....................................................................................

4.

8

C o n d u c t i v i t y C e l l ............................................ .....

18 £4

CHAPTER I THE PROBLEM AND DEFINITIONS I.

DEFINITIONS

The s u b j e c t o f b o n d in g i n c o o r d i n a t i o n (" com p lex" ) compounds h a s b e e n i n t r o d u c e d by T i e r n e y ,1 T a y l o r ,2 M a r t i n ,3 and C a r n e .4

T h is t h e s i s r e p r e s e n t s a c o n t in u a t io n o f th e

work o f C a r n e , who p r e p a r e d t h e compound S b c i 3 #3 N(CH3 ) 3 and made s u g g e s t i o n s f o r i t s f u r t h e r s t u d y .

The s u b j e c t h a s

b e e n b r o a d e n e d t o i n c l u d e t h e b e h a v i o r o f a r s e n i c and b is m u th t r i c h l o r i d e s to w a rd t r i m e t h y l © m i n e . t h e s e com pounds, i t

In d isc u ssin g

i s assum ed t h a t t h e am ine i s a t t a c h e d

t o t h e m e t a l atom b y a c o o r d i n a t e l i n k w h ic h w i l l be r e f e r r e d t o a s t h e d a t i v e bond i n t h i s p a p e r .

More

1 S. I . T i e r n e y , "A S t u d y o f t h e R e a c t i o n s o f P h o s p h o r u s P e n t a c h l o r i d e w i t h T r im e t h y la m in e ," ( u n p u b l i s h e d M a s t e r ’ s t h e s i s , U n i v e r s i t y o f S o u t h e r n C a l i f o r n i a , L os A n g e le s, 1 9 4 0 ). 2 J . C. T a y l o r , "An E x p e r im e n t a l S t u d y o f t h e P h o s p h o r u s C h l o r o n i t r i d e s and T h e i r R e a c t i o n s w i t h T r im e t h y l ami n e ( u n p u b l i s h e d M a s t e r ’ s t h e s i s , U n i v e r s i t y o f S o u t h e r n C a l i f o r n i a , L o s A n g e l e s , 1 940 ) • 3 L . L . M a r t i n , "The B e h a v i o r o f H e x a m e th y le n e T e t r a m ine Toward B oron F l u o r i d e , " ( u n p u b l i s h e d M a s t e r ’ s t h e s i s , U n iv e r s it y o f S ou th ern C a l i f o r n ia , Los A n g e le s , 1 9 4 0 ). 4 H. 0 . C a r n e , "The R e a c t i o n o f T r im e th y la m in e With Some I n o r g a n i c A c i d C h l o r i d e s , " ( u n p u b l i s h e d M a s t e r ’ s t h e s i s , U n i v e r s i t y o f S o u t h e r n C a l i f o r n i a , Los A n g e l e s , 1 9 4 1 ) .

2 e x p lic itly ,

a d a t i v e bond w i l l r e p r e s e n t t h e b o n d in g by

th e r e s id u a l e le c t r o n ic f o r c e s p r e s e n t in c o o r d in a tio n compounds and w i l l e x c l u d e t h e o r d i n a r y t y p e o f c o v a l e n t bond. X I. E a r l i e r w o rk .

THE PROELM!

The e a r l i e r work on t h i s s u b j e c t

d e a l t w i t h t h e amine r e a c t i o n o f p h o sp h o r u s c h l o r i d e s and o f a n tim o n y t r i c h l o r i d e .

T i e r n e y 5 showed t h a t t h e p h o s p h o r u s

c h l o r i d e s r e a c t w ith t r im e th y la m in e , b u t th e p r o d u c ts w ere not is o la t e d nor s e p a r a te ly i d e n t i f ie d .

C arne 5 s u c c e e d e d

i n p r e p a r i n g a compound h a v in g t h e fo r m u la S b C l 3 *3 N(CHg) 3 , but l e f t th e q u e s tio n o f i t s

stru ctu re u n se ttle d .

B t a t e m e n t o f t h e p r o b le m .

The p r e s e n t work was

u n d erta k en i n o r d e r t o stu d y th e tr im e th y la m in e a d d it io n r e a c t i o n s a l s o o f a r s e n i c and b is m u th t r i c h l o r i d e s . compounds r e s u l t i n g fro m t h i s

stu d y,

The

and a l s o t h e a n tim o n y

compound p r e p a r e d b y C a r n e , w e r e s u b j e c t e d t o f u r t h e r i n v e s t i g a t i o n , i n o rd er to f in d ex p e rim en ta l f a c t s i n g t h e i r s t a b i l i t i e s and i o n i c t e n d e n c i e s .

concern­

I t i s hop ed

t h a t t h e s e f a c t s w i l l h e l p show t h e n a t u r e and s t r e n g t h o f

5 T ier n e y , op.

c it.

6

Carne, o p . c i t .

3 t h e d a t i v e bond i n c o o r d i n a t i o n com pounds. Im p o r ta n c e o f t h e s t u d y .

The Werner t h e o r y o f

c o o r d i n a t i o n g r ew o u t o f su b -g r o u p co m p lex c h e m i s t r y .

B ut

s i n c e s i m i l a r c h e m i s t r y i s fo u n d among t h e e l e m e n t s o f t h e m ain g r o u p s , i t t o i n c l u d e th em .

i s im p o r t a n t to b r o a d e n t h e Werner t h e o r y M oreover,

s i n c e i t i s o b v i o u s t h a t com­

p ou n d s a r e now b e i n g s y n t h e s i z e d w h ose s t r u c t u r e s c a n n o t b e s a t i s f a c t o r i l y e x p l a i n e d by ev en t h e m ost r e c e n t c o n t r i b u ­ t i o n s t o s t r u c t u r a l t h e o r y , any work Tahich w i l l h e l p to s ta b iliz e ,

c la r ify ,

and d e v e lo p t h e f a c t u a l b ack gro u n d o f

t h i s t h e o r y i s o f g r e a t s i g n i f i c a n c e and d e s e r v e s t i m e and c o n s c ie n tio u s endeavor. Mode o f a t t a c k .

Some o f t h e p o s s i b l e

h a v i n g b e e n s y n t h e s i z e d and t h e i r e sta b lish e d ,

an'

compounds

c h e m ic a l f o r m u la e

a tte m p ts w i l l be made to d e t e r m in e t h e i r

s t a b i l i t i e s by s e e k i n g c o n d i t i o n s n e c e s s a r y f o r d e c o m p o sin g th em .

I p o r d e r t o i n v e s t i g a t e t h e b o n d in g a s tu d y o f t h e i r

i o n i c t e n d e n c i e s w i l l b e made by t e s t i n g t h e i r c o n d u c t i v i t i e s in liq u id

su lfu r d io x id e .

CHAPTER I I REVIEW OF THE LITERATURE A lth o u g h many com p lex compounds o f a r s e n i c and b ism u th a r e r e p o r t e d i n t h e l i t e r a t u r e , o n l y t h o s e w hich a r e co m p a ra b le t o t h o s e i n v o l v e d i n t h e p r e s e n t work w i l l be m e n t i o n e d . Gore^ o b s e r v e d a r e a c t i o n o f a r s e n i c t r i c h l o r i d e w i t h l i q u i d ammonia b u t g a v e no d e t a i l s .

P e r s o z 2 fo u n d a

w h i t e o r p a l e y e l l o w compound c o r r e s p o n d i n g t o t h e fo r m u la AsC1 3 *4(H H g)♦

R o s e 3 g a v e t h e f o r m u l a a s A sC lg -S iC H H g ); b u t

B e s s o n 4 c o n f ir m e d P e r s o z * d istille d

fin d in g s.

The t e t r a m m o n ia t e when

i n v a cu o a t 2 0 0 ° C. was fou n d by B e s s o n 5 and

R o s s e t 6 t o g i v e A sC l 3 *3^{HHg); w h ere a s AsClg*4(HH^) was t h o u g h t by H u g o t 7 t o b e a m i x t u r e o f ammonium c h l o r i d e and a r se n ic tr ia m id e .

1 2

G. G o r e , P r o c . R oy . S o c . , 2 1 : 1 4 1 , 1 8 7 3 . "" J . P e r s o z , Ann. Chem. P h y s . 2 e s e r i e , t , 4 4 : 3 2 0 , 1 8 3 0 .

3 H. R o s e , P o g g , Ann, t ,

52:62, 1841.

4 A. B e s s o n , Comp. R en d , 1 1 0 : 1 2 5 8 - 6 1 , 1 8 9 0 . 5 A. B e s s o n , Comp. R en d , 1 4 6 : 1 2 6 6 , 1 9 0 8 . 6 G. R o s s e t , Comp. Rend, 1 4 6 : 1 2 6 6 , 1 9 0 8 . 7 C. H u g o t, Comp. R en d , 1 3 9 : 5 4 - 5 6 , 1 9 0 4 .

5 G ore 8 fo u n d t h a t b is m u th t r i c h l o r i d e and l i q u i d ammonia r e a c t ,

D e h e r a i n c i t e d t h r e e a m in e s:

" 2 B iC l3 #RHg

a s t a b l e red h y g r o s c o p i c compound w h ic h w i l l m e l t and r e c r y s t a i D i z e ; B iC l 3 ’ 2 (KH3 ) , a d i r t y g r e e n s u b s t a n c e ; and B i C l g ^ t M j j ) , c o l o r l e s s ."9

A l l o f them form ammonium

c h lo r o b is m u th ite s i f t r e a t e d w ith h y d r o c h lo r ic a c id . F e a s i b i l i t y o f t h e p r o b le m .

As f a r a s c o u ld be

d e t e r m i n e d , n o t h i n g t h a t d i r e c t l y p a r a l l e l s t h e work w i t h ammonia h a s b e e n done w i t h t r i m e t h y l a m i n e and t h e f i f t h g ro u p t r i c h l o r i d e s , b u t t h e p r e v i o u s work 1 0 and t h e s i m i l i a r i t y o f t r i m e t h y l a m i n e and ammonia make t h e p r o b le m fe a sib le .

A l s o t h e c o n f u s i o n b e t w e e n p u re a d d i t i o n r e a c t i o n s

and a m m o n oly tie r e a c t i o n s makes i t

e v id e n t th a t th e u s e o f a

t e r t i a r y amine f o r su ch s t u d i e s w ould e l i m i n a t e a d i s t u r b i n g v a r ia b le .

The t r i c h l o r i d e s o f th e f i f t h grou p e le m e n t s

a r s e n i c , a n tim o n y and b is m u th w ere s e l e c t e d a s r e p r e s e n t a ­ t i v e s o f t h e e l e c t r o n r e c e p t o r (L e w is " a c id " )

p r i n c i p l e and

t r i m e t h y l a m i n e w as c h o s e n a s t h e e l e c t r o n d o n or (L e w is o r BE^nsted " b ase" )

su b stan ce.

The b a s i s f o r su ch a c h o i c e o f

8

G ore, op .

c i t . , 21:1 4 2 , 1873.

9 P . P . D e h e r a i n , Comp. Rend, 5 4 : 7 2 4 , 1 8 6 2 . 10 T a y l o r , T i e r n e y , and C a r n e ,

0£ .

c it.

r e a g e n t s h a s b e e n e x p l a i n e d by T ie r n e y * ^ and C a r n e .

11

T ie r n e y , on. c i t . , pp. 2 - 4 . 12 C arne,

0£

.

c i t . , pp. 5 -6 .

CHAPTER I I I REAGENTS PREPARED AND PURIFIED T r im e t h y l a m in e ,

The p r o c e d u r e o f T i e r n e y 1 was

m o d i f i e d by t h e i n t r o d u c t i o n o f a t a l l r e f l u x c o n d e n s e r fitte d

to a o n e - l i t e r b o ilin g f l a s k .

The am ine w as t h u s

d e l i v e r e d from t h e t o p o f t h e c o n d e n s e r w i t h so l i t t l e w a t e r t h a t t h e f i n a l p u r i f i c a t i o n by p h o s p h o r i c a n h y d r id e becam e e a s y . Carbon t e t r a c h l o r i d e and c h l o r o f o r m .

T hese s o lv e n t s

w e re d r i e d by d i s t i l l a t i o n from p h o s p h o r i c a n h y d r i d e . E th er.

Com m ercial a n h y d r o u s e t h e r w a s u s e d .

A r se n ic t r l c h l o r i d e .

T h i s w as p u r i f i e d by d i s t i l l a ­

t i o n from a m i x t u r e o f a r s e n i c t r i c h l o r i d e and a r s e n o u s o x i d e .2

On a c c o u n t o f t h e h y g r o s c o p i c and p o i s o n o u s n a t u r e

o f a r s e n i c t r i c h l o r i d e , t h e d i s t i l l a t i o n was d o n e i n t h e s e a l e d g l a s s a p p a r a t u s shown i n F i g u r e 1 .

Crude a r s e n i c

t r i c h l o r i d e w as p l a c e d i n a 50 m l . d i s t i l l i n g f l a s k

(A)

w h ic h was t h e n s e a l e d o f f a t ( B ) ; t h e n i t was d i s t i l l e d

1

T i e r n e y , oj}. c i t . , p p . 8 - 1 0 . E . W. W e r e a t t , C a n ., 2 2 3 : 8 5 9 , S e p te m b e r 1 9 , 1 9 2 2 ; Chem. A b s. , V o l . 1 6 , P a r t 2 , 4 3 0 4 , 1 9 2 2 .

8

FIGURE 1

9 t h r o u g h t h e s i x - i n c h c o n d e n s e r (C) i n t o t h e r e c e i v i n g fla sk

( D ) - ( a 12 5 m l . g . s . E r le n m e y e r f l a s k ) .

(E) was a

p l u g o f c o t t o n t o p r e v e n t a backw ash o f a i r and m o i s t u r e . B ism u th t r i c h l o r i d e .

R e a g e n t b is m u th t r i c h l o r i d e 3

was p r e p a r e d from b is m u th o x y c h l o r i d e and b is m u th h y d r a t e 4 by d i g e s t i n g t w i c e w i t h c o n c e n t r a t e d h y d r o c h l o r i d e a c i d and t h e n d i s t i l l i n g b is m u t h t r i c h l o r i d e away i n a s t r e a m o f n itr o g e n .

The a p p a r a t u s , n e c e s s a r i l y a l l g l a s s , i s

i n F ig u r e 2 .

shown

Crude b is m u th t r i c h l o r i d e w as i n t r o d u c e d i n t o

t h e 125 m l. d i s t i l l i n g f l a s k w h ic h w as t h e n s e a l e d o f f .

(A) th r o u g h t h e g l a s s tu b e (B) I t w as t h e n d i s t i l l e d

in a

s t r e a m o f d r y n i t r o g e n ( e n t e r i n g th r o u g h t h e in r s e a le d { g la s s tu b e (C ), in t o

th e r e c e i v i n g f l a s k

(D ).

S in c e b isa u th

t r i c h l o r i d e m e l t s a t 2 5 0 ° C . , i t was n e c e s s a r y t o k eep t h e e n tir e d i s t i l l i n g

3

a p p a r a t u s ab o v e t h a t t e m p e r a t u r e .

J . W. M e l l o r , A C o m p re h e n siv e T r e a t i s e o n I n o r g a n i c and T h e o r e t i c a l C h e m is t r y ( London: Longmans G reen a n 3 Company, 1 & 2 § ), 9 : 6 6 2 . 4 I. H. A r c h i b a l d , P r e p a r a t i o n s o f P u r e I n o r g a n i c S u b s t a n c e s (Hew York: J oh n W ile y and S o n s , I n c . , 1 9 3 2 ) , 2 7 7 .

10

FIGUHE 2

CHAPTER IV TECHNIQUE AND RESULTS OF INDIVIDUAL EXPERIMENTS T e ch n iq u e *

The p r o c e d u r e em p loy ed f o r t h e a d d i t i o n

o f t r i m e t h y l a m i n e t o t h e t r i c h l o r i d e s o f a r s e n i c , a n tim on y and b is m u t h , was i n ' some r e s p e c t s d i f f e r e n t from t h a t d e v e lo p e d b y Carne f o r t h e s y n t h e s i s o f S b C ls *3N(CH3 ) g .1 The m ost i m p o r t a n t ch a n g e w as i n t h e o r d e r o f t h e a d d i t i o n o f th e r ea c ta n ts:

h e r e t h e t r i m e t h y l a m i n e a lw a y s was p r e s e n t

i n e x c e s s o f t h a t r e q u i r e d f o r c o m p le t e r e a c t i o n . t r i m e t h y l a m i n e was d i s t i l l e d

in to th e r e a c tio n fla s k

( p r o t e c t e d by a p h o s p h o r i c a n h y d r id e d r y i n g t u b e ) d e n s e d by d r y i c e i n e t h e r .

The

and c o n ­

Then t h e d r y i n g t u b e w as removed

m o m e n ta r ily w h i l e a s o l u t i o n o f t h e c h l o r i d e w as a d d e d . C h lo r o fo r m was u s e d a s t h e s o l v e n t f o r a r s e n i c t r i c h l o r i d e and a n tim o n y t r i c h l o r i d e ,

as n e i t h e r tr im e th y la m in e n o r th e

m e ta l c h l o r i d e s r e a c t w i t h i t .

B ism u th t r i c h l o r i d e i s

i n s o l u b l e i n c h lo r o f o r m ; h e n c e e t h e r was a d o p te d a s a so lv e n t in i t s

case.

G l a s s - s t o p p e r e d E r le n m e y e r f l a s k s

w ere u s e d a s r e a c t i o n v e s s e l s w h en ev er t h e r e a c t i o n te m p e r a ­ t u r e was 0 ° C. o r b e lo w .

I f t h e r e a c t i o n t e m p e r a t u r e was

e x p e c t e d t o be above 0 ° C . ,

t h e r e a c t a n t s w e re s e a l e d i n a

1 C a r n e , oj>. c i t . , p p . 1 2 - 1 5 .

12 “bomb t u b e . M o i s t u r e , w h ic h w o u ld h a v e s e r i o u s l y a f f e c t e d t h e r e s u l t s , w as r i g o r o u s l y e x c l u d e d i n e v e r y c a s e . A n a l y t i c a l m e th o d .

I n t h e a n a l y s i s o f t h e com p oun ds,

an a t t e m p t w as made t o d i s p e n s e w i t h t h e c o m p le t e K ^ e ld a h l t e c h n i q u e and d i s t i l t r i m e t h y l a m i n e d i r e c t l y o u t o f a "basic so lu tio n .

S i n c e t h e b a s e h a s a l m o s t t h e same d i s s o c i a t i o n "

c o n s t a n t a s ammonia ( 7 . 4 x 10"® a g a i n s t 1 . 8 x 10"®) a t 2 5 ° C , , it

i s p o ssib le to t it r a t e i t

t o m e th y l o r a n g e , m e t h y l r e d

o r brom phenol b l u e end p o i n t s .

The f o l l o w i n g p r o c e d u r e was

em p loy ed t o a s c e r t a i n w h e t h e r t r i m e t h y l a m i n e w i l l d i s t i l c o m p le te ly :

a s o l u t i o n o f t r i m e t h y l a m i n e was a c i d i f i e d w i t h

b o r i c a c i d and f o u r s a m p le s w ere t a k e n .

Two o f t h e s e w ere

t i t r a t e d d i r e c t l y w ith stan d ard h y d r o c h lo r ic a c id . o t h e r t w o , 60 c . c .

To t h e

o f 4 0 p e r c e n t sodium h y d r o x i d e s o l u t i o n

w as added p r e p a r a t o r y t o d i s t i l l a t i o n on a K ^ e ld a h l a p p a ra tu s.

The d i s t i l l a t e was c a u g h t i n b o r i c a c i d s o l u t i o n ,

and t h e n t i t r a t e d w i t h s t a n d a r d h y d r o c h l o r i c a c i d .

S in ce th e

two m eth ods y i e l d e d i d e n t i c a l r e s u l t s , an a tt e m p t was made t o d e t e r m i n e t h e t r i m e t h y l a m i n e i n t h e c o m p le x e s d i r e c t l y by a d d in g 4 0 p e r c e n t sod ium h y d r o x i d e s o l u t i o n and d i s t i l l i n g in t o b o r ic a c id .

D e sp ite th e f a c t th a t i t

i s p o ssib le to

d i s t i l trim e th y la m in e q u a n t i t a t i v e l y , th e r e s u l t s i n th e c a s e o f a l l t h r e e c o m p le x e s w e re a b o u t 5 p e r c e n t lo w e r th a n t h o s e o b t a i n e d by t h e K j e l d a h l m ethod; c o n s e q u e n t l y t h e new

13 t e c h n i q u e w as abandoned i n f a v o r o f t h e o l d e r m eth o d . a r s e n i c t r l c h l o r i d e and t r i m e t h y l a m i n e .

Four

d i f f e r e n t e x p e r im e n ts w ere a ttem p ted w ith t h e s e r e a g e n ts :

A p r e l i m i n a r y t r i a l w a s made w i t h o u t • s o l v e n t : a r s e n i c t r i c h l o r i d e was d i s t i l l e d a t - 1 2 ° C*

i n t o l i q u i d tr im e th y la m in e

The r e a c t i o n was im m e d ia te and v i o l e n t ,

and

a lo n g w i t h c l o u d s o f w h i t e v a p o r , a w h i t e s o l i d fo r m e d . A f t e r t h e r e a c t a n t s had s t o o d a t 0 ° C. f o r f o r t y - e i g h t h o u r s , t h e e x c e s s t r i m e t h y l a m i n e was e v a p o r a t e d u n d e r vacuum.

Upon

s t a n d i n g , t h e p r o d u c t g r a d u a l l y t u r n e d from w h i t e t o b u f f i n c o lo r .

A n a l y s i s f o r n i t r o g e n i n d i c a t e d 7 . 0 3 p e r c e n t by

w e i g h t o r t h a t a p p r o x i m a t e l y o n e and o n e h a l f m o l e c u l e s o f t r i m e t h y l a m i n e had added t o o n e o f a r s e n i c t r i c h l o r i d e , r e p r e s e n t e d by t h e fo r m u la 2 A sC l 3 ?3H(CH3 ) T h i s

as

r e la tiv e ly

u n c e r ta in r e s u l t l e d t o th e a d o p tio n o f a tec h n iq u e in v o lv in g a s o lv e n t. I n t h e s e c o n d e x p e r im e n t a s o l u t i o n o f a r s e n i c t r i ­ c h l o r i d e i n c h l o r o f o r m w as added t o t r i m e t h y l a m i n e a t - 8 0 ° C . , i n a bomb t u b e vdiich was t h e n s e a l e d .

The bomb was

a l l o w e d t o s t a n d a t room t e m p e r a t u r e f o r s i x d a y s d u r in g w h ic h a w h i t e s o l i d form ed and s l o w l y t u r n e d y e l l o w .

The

s o l v e n t and e x c e s s t r i m e t h y l a m i n e w ere e v a p o r a t e d , f i r s t a t o r d i n a r y p r e s s u r e and f i n a l l y i n v a c u o .

A n a ly sis fo r

n i t r o g e n i n d i c a t e d 6 . 6 4 p e r c e n t by w e i g h t o r one m o l e c u l e

14 o f a r s e n i c t r i c h l o r i d e a d d in g b e t w e e n one and o n e h a l f m o le c u le s o f tr im e th y la m in e . I n a t h i r d e x p e r im e n t a s o l u t i o n o f a r s e n i c t r i c h l o r i d e i n c h l o r o f o r m was added t o l i q u i d t r i m e t h y l a m i n e a t - 8 0 ° C. and t h e r e a c t a n t s k e p t a t 0 ° C* f o r f o u r d a y s . w h i t e s o l i d form ed b u t t u r n e d b u f f when t h e s o l v e n t s w ere removed u n d e r vacuum.

In t h i s ca se th e f i n a l product

l o o k e d l i k e a m i x t u r e o f w h i t e and y e l l o w s u b s t a n c e s , f o r s e p a r a t e c r y s t a l s showed b o th c o l o r s .

A n a ly sis for

n it r o g e n in d ic a t e d 1 0 .4 p er cen t by w e ig h t o r one m o le c u le o f a r s e n i c t r i c h l o r i d e a d d in g two and o n e h a l f m o l e c u l e s o f tr im e th y la m in e . I n o r d e r t o g e t more r e p r o d u c i b l e r e s u l t s ,

th e f in a l

compound o f t h e t h i r d e x p e r im e n t was w ashed w i t h l i q u i d s u l f u r d i o x i d e w h ic h w a s t h e n rem oved b y vacuum a t ab ou t 8 0 ° C.

S i n c e i t w as fo u n d t h a t t h i s t r e a t m e n t w ou ld n o t

decom p ose t h e c o m p le x , i t was t h o u g h t t h a t t h e l a s t t r a c e s o f s o l v e n t and p e r h a p s o t h e r i m p u r i t i e s c o u l d t h u s b e rem oved w i t h o u t dam age.

I n l i q u i d s u l f u r d i o x i d e t h e com­

p l e x t u r n e d w h i t e , b u t f i n a l l y a y e l l o w compound formed w h ic h had an e s t e r i c o d o r .

A n a l y s i s f o r n i t r o g e n showed

1 1 . 7 2 p e r c e n t by w e i g h t o r a compound r e p r e s e n t e d by t h e fo r m u la A sC l 3 *5N(CHg) T h i s compound fu m es i n a i r , y i e l d s arsendicr, t r i ­ c h l o r i d e on t r e a t m e n t w i t h c o n c e n t r a t e d s u l f u r i c a c i d , i s

A

15 e x t r e m e l y h y g r o s c o p i c , h a s an e s t e r i c o d o r and i s c o m p le te ly s o lu b le i n w a te r .

The f o u r e x p e r i m e n t s showed

t h e p o s s i b i l i t y o f w h i t e and y e l l o w c o m p l e x e s , b u t o n l y t h e y e l l o w i l s C l 3 *3N(CH3 ) 3 , was a c t u a l l y i d e n t i f i e d .

The

f a c t t h a t AsClg*3N(CHg ) 3 t u r n s w h i t e i n an e x c e s s o f l i q u i d s u lfu r d io x id e i s

e v id e n c e o f d e c o m p o sitio n o r th e

e x i s t e n c e o f a w h i t e com p lex o f l o w e r t r i m e t h y l a m i n e c o n ­ ten t.

The d a t a e s t a b l i s h i n g t h e f o r m u la e f o r t h e s e c o m p le x e s

a r e sum m arized i n T a b le I . A n tim on y t r i c h l o r i d e and t r i m e t h y l a m i n e .

The p r o ­

c e d u r e f o l l o w e d h e r e w as i d e n t i c a l w i t h t h a t o f C a r n e ,^ w i t h t h e e x c e p t i o n n o te d on p a g e

11.

On a n a l y s i s f o r n i t r o g e n , i t w as fou n d t h a t on e m o l e c u l e o f a n tim o n y t r i c h l o r i d e had added t h r e e m o l e c u l e s o f t r i m e t h y l a m i n e , S b C l 3 *3N(CH3 ) 3 , i n a g r e e m e n t w i t h C a r n e ’ s r e su lt. B ism u th t r i c h l o r i d e and t r i m e t h y l a m i n e .

S in ce

b is m u th t r i c h l o r i d e i s i n s o l u b l e i n c h l o r o f o r m , t h e l i t e r a ­ t u r e was s e a r c h e d f o r a s o l v e n t .

E t h e r was s e l e c t e d b e c a u s e

o f i t s l o w b o i l i n g p o i n t and e a s y a v a i l a b i l i t y i n p u r e f o r a , and i t s

i n e r t n e s s to tr im e th y la m in e .

I t w as assumed t h a t -

any e t h e r a t e w h ic h m ig h t be form ed w ou ld b e t o o u n s t a b l e t o

2 C a r n e , o£ .

c it.,

p . 14

16 TABLE I DATA ESTABLISHING FORMULAE OF COMPLEXES

P o s s i b l e c o m p le x e s

T h eo r etic a l P er cent Per cent Amine %

A ctu al Per cen t Per c e n t Amine N2

FOR ARSENIC AsCl«z*N(CHw)