The Mechanism of the Hypophosphorus Acid Deamination Reaction

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n73 (

PUK DU E UNIVERSITY

THIS IS TO CERTIFT THAT THE T H ESIS PREPARED U N D E R MY SU PER V ISIO N

BY

Glenn D ale Cooper

ENTITLED

THE MECHANISM OF THE HYPOPHOSPHOROUS

ACID DEAMINATION REACTION

COMPLIES WITH THE UNIVERSITY REGULATIONS O N GRADUATION T H E SE S

AND IS APPROVED BY ME A S PULITLLING THIS PART O F THE REQUIREM ENTS

FO R THE D EG R EE O F

D octor o f P h ilo so p h y

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TO TH E LIBRARIAN;----

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THIS T H ESIS IS NOT TO B E REGARDED A S CONFIDENTIAL.

PR O FESSO B

G R A B . S O B O O Ii F O R M 0 —3 . 4 9 —IM

OHABOR

THE MECHANISM OF THE HYPOPHOSPHOROUS ACID DEAMINATION REACTION

A T h e s is S u b m itted t o th e F a c u lty ofPurdue U n iv e r s it y

by

G lenn D. Cooper

I n P a r t i a l F u lf i llm e n t o f th e R eq u irem en ts f o r t h e D egree of D o c to r o f P h ilo s o p h y A u g u st, 1949

ProQuest Number: 27712207

All rights reserved INFORMATION TO ALL USERS The q u a lity of this re p ro d u c tio n is d e p e n d e n t u p o n the q u a lity of the co p y su b m itte d . In the unlikely e v e n t that the a u th o r did not send a c o m p le te m a n u scrip t and there are missing p a g e s, these will be n o te d . Also, if m a te ria l had to be re m o v e d , a n o te will in d ic a te the d e le tio n .

uest P roQ uest 27712207 Published by ProQuest LLO (2019). C o p y rig h t of the Dissertation is held by the A uthor. All rights reserved. This work is p ro te cte d a g a in s t u n a u th o rize d co p yin g under Title 17, United States C o d e M icroform Edition © ProQuest LLO. ProQuest LLO. 789 East Eisenhower Parkway P.Q. Box 1346 Ann Arbor, Ml 4 8 1 0 6 - 1346

AOOOWLEDGMEKT

The a u th o r w is h e s t o e x p r e s s h i s s in c e r e a p p r e c ia t io n t o h i s r e s e a r c h d i r e c t o r . Dr. N athan Kornblum, f o r t h e a s s i s t a n c e and i n s t r u c t i o n w hich h e g a v e d u rin g t h e c o u r se o f t h is research . The a u th o r w is h e s t o acknow ledge h i s in d e b te d n e s s t o th e Purdue R e sea rch F o u n d a tio n f o r f i n a n c i a l a s s i s t a n c e i n th e form o f an XR f e l l o w s h i p .

TABLE OF CONTENTS Page ABSTRACT ...............................................................................................................

i

INTRODUCTION AND DISCUSSION ..................................................................

1

EXPERIMENTAL.....................................................................................................

32

P r e p a r a tio n o f D iazonium S a l t s ..............................................

32

A pparatus and T ech n iq u e ...............................................................

35"

R e d u c tio n o f p -T o ly ld ia z o n iu m H ydrogen S u l f a t e . . . .

38

D e co m p o sitio n o f p -T o ly ld ia z o n iu m H ydrogen S u l f a t e i n W a t e r ............................................... ...................

48

E f f e c t o f V a rio u s In o r g a n ic Compounds on th e Re­ d u c t io n o f p -T o ly ld ia z o n iu m Hydrogen S u lf a t e a t 1 3 .8 ° .................................................................... R e d u c tio n o f p -A n is y ld la z o n lu m H ydrogen S u l f a t e . . .

53

59

E f f e c t o f Q uinones on t h e R e d u c tio n o f p - T o l y l d iazon iu m H ydrogen S u lf a t e ......................................

70

R e d u c tio n o f ;^ -N itro b en zen ed ia zo n iu m H ydrogen S u l f a t e .......................................................................

83

R e d u c tio n o f P entahrom ohenzenedlazoniurn H ydrogen S u l f a t e .........................................................................................

93

C a t a ly s is o f t h e R e d u c tio n o f I n a c t iv e D iazonium S a l t s by T ra ces o f Very R e a c tiv e D iazonium S a l t s .............................................................................................. R e d u c tio n o f B enzoquinone by Hypophosphoroue A cid

.

96 99

E f f e c t o f Copper S u l f a t e on th e Y ie ld o f T o lu en e i n th e R e d u c tio n o f p -T o ly ld ia z o n iu m H ydrogen S u lf a t e ...........................................................................................

100

R e d u c tio n s w ith P h osphorous A c i d .......................................... 103 R e d u c tio n o f p -T o ly ld ia z o n iu m Hydrogen S u l f a t e i n t h e A bsence o f L ig h t ................................................... R e d u c tio n o f B en zen ed iazon iu m Hydrogen S u l f a t e

105

....

106

BIBLIOGRAPHY.....................................................................................................

107

V IT A ........................................................................................................................

LIST OF FIGURES F ig u r e

Page

1.

R e p r o d u c ib ilit y o f r a t e d e te r m in a t io n s ............................

3

2.

R a tes o f r e d u c tio n o f d ia zo n iu m s a l t s a t 13 . 8 ° . . . .

6

3.

C a t a ly s is o f th e r e d u c t io n o f o - n it r o b e n z e n e d iazon iu m h y d ro g en s u l f a t e a t 0 ° .............................

9

C a t a ly s is o f th e r e d u c tio n o f p - t o ly ld ia z o n iu m h y d ro g e n s u l f a t e a t 13 *8 ° ..............................................

10

C a t a ly s is and i n h i b i t i o n o f th e r e d u c t io n o f p a n is y ld ia z o n iu m h y d ro g en s u l f a t e a t 13 . 8 ® . . . .

11

C a t a ly s is and i n h i b i t i o n o f th e r e d u c t io n o f p a n is y ld ia z o n iu m h y d ro g en s u l f a t e a t 0° ...............

12

I n h i b i t i o n o f r e d u c t io n o f p - a n is y ld ia z o n iu m h yd rogen s u l f a t e by b en zo q u in o n e a t 13 , 8 ® . . . .

14

I n h i b i t i o n o f r e d u c tio n o f p - t o ly ld ia z o n iu m h y d ro g en s u l f a t e by b en zo q u in o n e a t 13 *8 ® . . . .

15

R e d u c tio n o f p - t o ly ld ia z o n iu m h y d ro g en s u l f a t e i n t h e p r e se n c e o f b en zo q u in o n e and cop p er s u l f a t e ................................................... * ..................................

16

E f f e c t o f b en zoq u in o n e on t h e r e d u c tio n o f p - n i t r o b e n zen ed ia zo n iu m h yd rogen s u l f a t e a t 0® .............

17

E f f e c t o f b en zoq u in o n e on th e r e d u c t io n o f p e n t a brom obenzenediazonium h y d ro g en s u l f a t e a t 0 ° .

18

C a t a ly s is o f th e r e d u c t io n o f p -A n is y ld ia z o n iu m h y d ro g en s u l f a t e by p -n itr o b e n z e n e d ia z o n iu m h y d ro g en s u l f a t e ....................................................................

22

C a t a ly s is o f th e r e d u c tio n o f p - t o ly ld ia z o n iu m h y d ro g en s u l f a t e by p -n itr o b e n z e n e d ia z o n iu m h yd rogen s u l f a t e ....................................................................

23

C a t a ly s is o f th e r e d u c tio n o f p - t o ly ld ia z o n iu m h yd rogen s u l f a t e by pentab rom ob en zen ed iazon iu m h yd rogen s u l f a t e ....................................

24

R e d u c tio n a p p a ra tu s ..........................................................................

36

4. 5. 6.

7. 8.

9.

1 0. 11. 12 .

13»

14.

15.

LIST OF TABLES T ab le 1. 2.

3.

Page R ate o f d e c o m p o s itio n o f p - t o ly ld ia z o n iu m h y d ro g en s u l f a t e i n w a te r a t 40® ..............................

5

E f f e c t o f v a r io u s s u b s ta n c e s on t h e r a t e o f r e d u c t io n o f p - t o ly ld ia z o n iu m h y d ro g en s u l f a t e .........................................................................................

7

E f f e c t o f p r e tr e a tm e n t o f b en zo q u in o n e w ith hypophosphoroue a c id on th e le n g t h o f th e i n h i b i t i o n p e r i o d .................................................................

27

(C o n t r ib u tio n from t h e D epartm ent o f C h em istry and t h e Purdue R e se a rc h F o u n d a tio n , Purdue U n iv e r s it y , L a f a y e t t e , I n d ia n a ) THE MECHANISM OF THE HYPOPHOSPHOROUS ACID DEAMINATION REACTION By N athan Kornblum and G lenn D. Cooper^ 1.

From t h e

Ph. D. t h e s i s o f G lenn D. C ooper, Purdue

U n iv e r s it y .

AN ABSTRACT The r e d u c t io n o f a d ia zo n iu m s a l t by h yp op h osp h orou s a c id i s a r e a c t i o n i n w hich th e d ia zo n iu m group i s r e p la c e d by h y d ro g en .

Inasm uch a s d ia zo n iu m s a l t s a r e r e a d i l y ob­

t a in e d from a r o m a tic p rim ary a m in es, t h e o v e r a l l r e s u l t i s a sim p le and e f f e c t i v e p ro ced u re f o r r e p la c in g an a r o m a tic p prim ary amino group by h yd rogen : 2.

Kornblum i n Adams' "O rganic R e a c tio n s ," John W iley and S o n s, I n c . , New Y ork, N. Y . , 1 9 4 4 , V o l. I I , pp. 2 7 7 -2 8 2 .

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R e c e n tly

The r e s u l t s w hich a r e

A lex a n d er and Burge ( p r iv a t e com m u n ication )

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h ave fou n d b ip h e n y l and te r p h e n y l among t h e p r o d u c ts o f t h e h yp ophosph orou s a c id r e d u c t io n o f b e n z e n e d ia z o n iu m c h lo r id e and h a v e s u g g e s te d t h a t t h e fo r m a tio n o f t h e s e b y -p r o d u c ts i n v o l v e s f r e e r a d i c a l s . p r e s e n te d i n t h i s p a p er v e r y s t r o n g ly s u g g e s t t h a t t h e h yp o­ phosphorous a c id r e d u c t io n o f d ia zo n iu m s a l t s i s a f r e e r a d ic a l c h a in r e a c t i o n . The p r e s e n t s tu d y was i n i t i a t e d by t h e o b s e r v a t io n t h a t th e hyp ophosph orou s a c id r e d u c tio n o f 2.-t o ly ld ia z o n iu m h yd rogen s u l f a t e i s p r o fo u n d ly c a t a ly z e d by s m a ll am ounts o f c e r t a i n o x id i z in g a g e n t s , su ch a s p o ta ss iu m perm anganate and p o ta ssiu m d i chrom âte .^ 4.

I n o r d e r t o o b t a in more d e t a i l e d

T a y lo r , Ph. D. T h e s i s , Purdue U n iv e r s it y , 1947*

in fo r m a tio n about t h i s c a t a l y s i s , th e k i n e t i c s o f t h e un­ c a t a ly z e d r e a c t i o n were f i r s t s t u d ie d .

The s a l t s em ployed

were a n a l y t i c a l l y p u r e , c r y s t a l l i n e p - t o ly ld ia z o n iu m h y d ro g en s u l f a t e , p - a n is y ld ia z o n iu m h y d ro g en s u l f a t e , p - n it r o b e n z e n e diazonium h yd rogen s u l f a t e and pen tab rom ob en zen ed iazon iu m h yd rogen s u l f a t e . I n no in s t a n c e c o u ld r e p r o d u c ib le r e s u l t s be o b t a in e d , even th ou gh v e r y c o n s id e r a b le e f f o r t s w ere made t o in s u r e I d e n t i t y o f c o n d it io n s .

P ig . 1 i l l u s t r a t e s t h e v a r i a t i o n

o b se rv e d when sam p les o f a f r e s h l y p r ep a red b a tc h o f p t o ly ld ia z o n iu m h yd rogen s u l f a t e were t r e a t e d w ith h y p o p h o s­ phorous a c id un der " i d e n t i c a l c o n d it io n s ."

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F ig . 8 I n h i b i t i o n o f t h e R é d u c tio n o f ^ ^ T o ly ld la z o n iu m H ydrogen S u lf a t e by B enzoquinone a t 1 3 . 8 ° . The r e a c t i o n m ix tu r e c o n ta in e d 1 /2 0 0 m ole o f ^ - t o l y l diazon iu m h y d ro g en s u l f a t e , 1 /4 0 0 0 m ole o f ^ -b e n z o q u in o n e , and 1/20 mole o f hyp op h osp h orou s a d d ; t o t a l volum e 20 m l.

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Hours F ig . 9 R e d u c tio n o f £ -T o ly ld ia z o n iu n i Hydrogen S u l f a t e i n th e P r e se n c e o f ^ -B en zo q u in o n e and Popper S u l f a t e . The r e a c t io n m ix tu re c o n ta in e d 1 /2 0 0 mole o f £ - t o l y l diazonium h y d ro g en s u l f a t e , 1/20 m ole h yp ophosph orou s a c id , and 1 /4 0 0 0 mole o f p.-benzoquin one i n 20 m l. o f s o l u t i o n . The tem p era tu re was 1 ) . 8 0 . At t h e p o in t marked by a c r o s s 1 /4 0 0 0 mole o f co p p er s u l f a t e was added.

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E f f e c t o f p -B en zoq u ln o n e on th e R e d u c tio n o f o - N l t r o b en z e n e d la z o n iu m H ydrogen S u l f a t e a t 02.. O 1 /4 0 0 m ole ^ -n itr o b e n z e n e d ie z o n iu m h y d ro g en s u l f a t e , 1 /4 m ole hyp ophosph orou s a c id ; t o t a l volum e 100 m l. • 1 /4 0 0 m ole £ -n ltr o b e n z e n e d ia z o n lu m h y d ro g en s u l f a t e , 1 / 4 m ole hyp ophosph orou s a c id , and 1/200 m ole p -b e n z o q u ln o n e ; t o t a l volum e 100 m l.

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M lnutes F ig . 11 E f f e c t o f BenzoQ ulnone on th e R e d u c tio n o f Pentabrom ob en zen ed la zo n iu m Hydrofcen S u lf a t e a t 1 3 . 8 ° . # TV400 m ole p en tab rom ob en zen ed iazon iu m h y d ro g en s u l f a t e , 1 / 4 m ole hyp ophosph orou s a c id ; t o t a l volum e 100 m l. o 1 /4 0 0 m ole pentabrom obenzenediazonium h yd rogen s u l f a t e , 1 / 4 m ole hyp ophosph orou s a c i d , 1/8000 m ole (5 m ole p e r c e n t ) £ -b e n z o q u ln o n e ; t o t a l volum e 100 m l. Q 1 /4 0 0 mole p en tabrom obenzenediazonium h y d ro g en s u l f a t e , 1 /4 m ole hypophosphorous a c id , 1/200 m ole (200 mole p e r c e n t ) p -b e n z o q u ln o n e ; t o t a l volum e 100 m l.

x lx

d l chrom âte a r e c a p a b le o f c o n v e r t in g t h e ^ - a n is y ld ia z o n iu m s a l t , o r a r e a c t i o n p r o d u c t, e . g . , a n i s o l e o r p -h y d r o x y a n i s o l e , t o a q u in on e o r a s e m iq u in o n e , t h e i n h i b i t i o n , w hich i s o b s e r v e d o n ly w ith t h i s d ia zo n iu m s a l t , becom es u n d er­ s ta n d a b le .

T h is e x p la n a t io n i s su p p o rted by t h e o b s e r v a t io n

t h a t c a t a l y s t s v h lc h a r e m ild o x id i z in g a g e n t s , su ch a s cop p er s u l f a t e and sodium n i t r i t e , s im p ly c a t a ly z e t h e r e ­ d u c t io n o f 2 - a n is y ld ia z o n iu m h y d ro g en s u l f a t e . The f o r e g o in g f a c t s , a s w e ll a s o t h e r s w hich a r e p r e ­ s e n te d i n t h e s e q u e l, do n o t a p p ea r t o be c a p a b le o f e x ­ p la n a t io n on any b a s i s o th e r th a n t h a t o f a f r e e r a d i c a l c h a in r e a c t i o n . 7.

The f o ll o w i n g m echanism i s s u g g e s te d :^

Minor m o d if ic a t io n s o f t h i s schem e a r e e a s i l y e n v is io n e d . For e x a m p le , i n t h e c h a in p r o p a g a tin g seq u e n c e: Ar*

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, th u s in c r e a s in g t h e te n d e n c y o f t h e

diazon iu m io n t o go o v e r t o a c o v a le n t s t r u c t u r e su ch a s Ar-E=N-OH, Ar-NsN-OPOHg, o r , i n t h e p r e s e n c e o f 01 “ , Ar-EsN -01.® 8.

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The r a t e o f t h e hypophosphorous a c id r e d u c t io n o f

d iazon iu m s a l t s i s c o n s id e r a b ly in c r e a s e d by la r g e am ounts o f h a li d e i o n .^

T h is i s n o t a s a l t e f f e c t , s in c e e q u iv a le n t

q u a n t it ie s o f o th e r io n s c a u se no in c r e a s e i n t h e r a t e . presum ably w ould a l s o s e r v e t o r e n d e r t h e

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a c c e p t an e l e c t r o n from H gPO ^. 2l I t h a s b e e n o b se r v e d t h a t th e r a t e o f r e d u c t io n o f p - t o ly ld ia z o n iu m h yd rogen s u l f a t e i s lo w e r e d by th e a d d it i o n o f HgSO^j. o r H^PO^; t h i s i s c o n s i s t e n t w ith e i t h e r o f t h e p rop osed i n i t i a t i o n s t e p s .

I n r e a c t i o n ( 3 ) t h e c o n c e n t r a t io n

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o f oovaleiïfc d ia z o compound would d e c r e a s e a s t h e a c i d i t y o f t h e sy ste m i s I n c r e a s e d w h ile s t e p (4 ) w ould be a d v e r s e ly a f f e c t e d b e c a u s e o f th e d im in u tio n i n t h e c o n c e n t r a t io n o f th e H2PO2' io n , A p h o to c h e m ic a l d i s s o c i a t i o n o f h yp ophosph orou s a c id H jP O g

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i s n o t t h e i n i t i a t i n g r e a c t i o n , s in c e t h e r e d u c t io n o f p t o ly ld ia z o n iu m h yd rogen s u l f a t e p r o c e e d s a t th e u s u a l r a t e i n co m p lete d a r k n e s s .

A th e r m a l d i s s o c i a t i o n cfT th is ty p e

ap p ears n o t t o b e in v o l v e d , s l n o e ^ i f i t were t h e m ajor i n i t i a t i n g s t e p , t h e r a t e o f i n i t i a t i o n w ould be in d ep en d e n t o f t h e p a r t i c u l a r d ia zo n iu m s a l t p r e s e n t so t h a t t h e c a t a l y s i s o f t h e r e d u c t io n o f u n r e a c t iv e d ia zo n iu m s a l t s by t r a c e s o f more a c t i v e o n es ( F ig s . 1 2 , 1 3 , l 4 )

c o u ld n o t b e e x p la in e d ,

A most a t t r a c t i v e f e a t u r e o f t h e p r o p o se d mechanism i s th e s im p le e x p la n a t io n i t a f f o r d s o f t h e p ro fo u n d c a t a l y t i c e f f e c t w hich a number o f o x id i z in g a g e n ts h a v e upon t h e hypophosphorous a c id r e d u c t io n o f d ia zo n iu m s a l t s . ^ 9.

P o ta s-

T h is c a t a l y s i s o f a r e d u c t io n by o x id i z i n g a g e n ts i s r e m in is c e n t o f t h e u s e o f red o x sy ste m s i n c a t a ly z in g v i n y l p o ly m e r iz a t io n s , r e a c t io n s w h ich , i t i s g e n e r a ll y a g r e e d , p r o c e e d v i a a f r e e r a d i c a l c h a in m echanism .

slum p erm an gan ate, p o ta ss iu m d ich ro rn a te, m e t a l l i c c o p p e r , and c u p r lc s u l f a t e a r e v e r y p o w e r fu l c a t a l y s t s ; m anganese d io x id e and sodium n i t r i t e a r e somevdiat l e s s a c t i v e , w h ile m e r cu ric

«30

10

1.0

0 .5

1 .5

Hours F ig . 12 G a ta ly a ifl o f t h e R e d u c tio n o f

A n la y Id la zo n lu m

Hydrogen S u l f a t e by ]^ ~N ltrob en zen ed l a zonlum Hzdro&en S u lf a t e a t 1 M Î * The r e a c t i o n m ix tu re c o n ta in e d 1/200 m ole ;^ ^ a n isy ldlazonlum h yd rogen s u l f a t e and 1/20 m ole hyp ophosph orou s a c id . At th e p o in t marked by a c r o s s 1 /4 0 0 0 m ole £ - n l t r o b en zen ed lazon lu m h y d ro g en s u l f a t e was added. The volum e o f n it r o g e n c o r r e sp o n d in g t o th e co m p le te d e c o m p o s itio n o f 1 /4 0 0 0 m ole o f d iazon iu m s a l t I s 5 .6 ml.

20

1.0

0 .5

1 .5

Hours F ig . 13 C a t a ly s is o f t h e R e d u c tio n o f £ » T o ly ld ia zQ n iu m Hydrogen S u lf a t e by

ro b en zen ed ia zo n iu m Hydrogen S u lfa te

1 3 .8 ° .

The r e a c t i o n m ix tu r e c o n ta in e d 1 /2 0 0 mole £ - t o l y l diazonium h yd rogen s u l f a t e and 1/20 mole hyp ophosph orou s a c id ; t o t a l volum e 20 m l. At th e p o in t marked by a c r o s s 1 /4 0 0 0 mole o f 2,-n itr o b e n z e n e d ia z o n iu m h y d ro g en s u l f a t e was added. The volum e o f n it r o g e n c o r r e sp o n d in g t o th e c o m p le te d e c o m p o sitio n o f 1 /4 0 0 0 m ole diazon iu m s a l t i s 5*6 m l.

70

20

10

1.0

0 .5 Hours F ig . 14 O a ta ly a ls o f t h e R éd u ctio n o f

Hydrogen

S u lf a t e by P entabrom obenzenediazonium HydroRen S u l f a t e at 1 5 .8 ° . The r e a c t i o n m ix tu r e c o n ta in e d 1/200 mole 2L -to ly ld ia z o n iu m hydrogen s u l f a t e and 1/20 mole hyp ophosph orou s a c id ; t o t a l volume 20 m l. At t h e p o in t marked by a c r o s s 1 /4 0 0 0 m ole p e n t a brom obenzenediazonlum h yd rogen s u l f a t e was added. The volum e o f n it r o g e n c o r r e sp o n d in g t o th e co m p lete d e c o m p o s itio n o f 1 /4 0 0 0 mole d iazon iu m s a l t i s 5*6 m l.

XXV

s u l f a t e shows s l i g h t b u t u n m ista k a b le c a t a l y t i c a c t i v i t y . C a t a ly s is i s p resu m ab ly due do a o n e - e l e c t r o n o x i d a t io n o f h yp ophosph orou s a c id o r t h e h y p o p h o sp h ite io n .

The f r e e

r a d i c a l s so p rod u ced r e a c t w ith t h e d ia zo n iu m io n a c c o r d in g t o ( 6 ) , th u s s t a r t i n g th e c h a in .

For e x a m p le , w ith

th e r e a c t i o n w ould b e: 0U++

10.

The

+

HgPOg"

___ ► OU*

t

[ HgPOg ] '

fH gfO g1 ’ r a d i c a l p ro d u ced i n r e a c t i o n s (4 ) and

( 8 ) w ould n o t h ave t h e same s t r u c t u r e a s t h a t o f e q u a tio n (5 ) i f , a s seem s l i k e l y , a P-H bond r a t h e r th a n an 0-H bond i s b ro k en i n (5 )«

The h y p o p h o sp h ite

r a d i c a l o f ( 5 ) w ould h a v e t h e s t r u c t u r e

qjj Ô©

w h ile t h a t produ ced by r e a c t i o n ( 8 ) w ould be

r

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