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THE THERMAL DECOMPOSITION OF N-BUTYLAMINE

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T H IS D IS S E R T A T IO N H A S BEEN M IC R O F IL M E D E X A C T L Y AS R E C E IV E D .
L ib r a r y
N . Y.
u k iv ;
THE THERMAL DECOMPOSITION OF N-BUTYLAMINE
A T h e s is
S u b m i t te d i n P a r t i a l F u l f i l l m e n t
o f t h e R e q u ir e m e n t s f o r t h e
D e g re e
of
D o cto r o f P h ilo s o p h y
at
New Y o rk U n i v e r s i t y
by
H a r o ld C h a r l e s B e a c h e l l . LI.A.
A p r i l 1941
PLEASE NOTE:
Some pages may have
in d is tin c t
F i l m e d as
U n iversity
M icrofilm s,
p rin t.
received.
A Xerox
E d u c a t i o n Company
TABLE OF CONTENTS
Page
In tro d u c tio n .
.............................................................................
1
E x p e rim e n ta l.
P art I .
A p p a r a t u s and P r o c e d u r e ............................ 7
P art I I .
D a ta.
....................................................................12
(A)
S t a t i c . .............................................. 12
(B)
Dynamic
.........................................18
D i s c u s s i o n ...............................................................................................23
Summary...................................................................................................... 27
B i b l i o g r a p h y ............................
28
ACKNOWLEDGEMENT
The a u t h o r w i s h e s t o e x p r e s s
h is a p p re c ia tio n to
P r o f e s s o r H. A. T a y l o r
f o r h i s h e l p f u l c r i t i c i s m and
c o n s ta n t e n co u rag em en t.
1.
INTRODUCTION
The d e c o m p o s i t i o n o f a m in e s h a s r e c e n t l y r e c e i v e d
in c re a se d a tte n tio n .
The p r e s e n t r e s e a r c h i s t h e f i r s t
r e p o r te d p y r o l y s i s o f n -b u ty la m in e •
I n v ie w o f t h e r e ­
c e n t l y proposed m e c h a n i s m - * - f o r th e e le m e n ta ry a c t
i n t h e d e c o m p o s i t i o n o f co m p lex m o l e c u l e s o f t h i s t y p e ,
s u c h a s t u d y s h o u l d be o f a p p r e c i a b l e i n t e r e s t .
The lo w e r members o f t h e am ine s e r i e s h a v e r e ­
c e i v e d t h e m o st e x t e n s i v e i n v e s t i g a t i o n .
M u ller found
t h a t t h e p r o d u c t s o f d e c o m p o s i t i o n o f m e th y la m in e a t
1 2 0 0 ° w ere amm onia, h y d ro g e n c y a n i d e , m e th a n e * h y d ro g e n
and n i tr o g e n .
Jo lley 5 > 6 > 7 , s t u d ie d th e p y r o ly s is a t
536°C and o b t a i n e d h y d r o g e n , h y d r o g e n c y a n i d e , m ethane
a n d am m onia^but no n i t r o g e n .
He c o n c l u d e d t h a t t h e p r o ­
c e s s o f d e c o m p o s i t i o n was " r e l a t i v e l y s i m p l e " .
T h is
d o e s n o t seem t o be b o rn e o u t i n t h e work o f T r a v e r s ,
who fo u n d a t 520 - 5 4 0 °C t h a t t h e p r i m a r y s t e p was i n ­
f l u e n c e d by s u r f a c e and t h e r e s u l t s c o u l d n o t be r e p r o ­
duced9
The p h o t o l y s i s ^ o f m e th y la m in e y i e l d s h y d r o g e n ,
am m o n ia,m eth an e, and n i t r o g e n a s g a s e o u s p r o d u c t s .
The d im e th y la m in e d e c o m p o s i t i o n was s t u d i e d by
T a y l o r -*-®, who c o n c l u d e d t h e p r o c e s s was c o m p l i c a t e d ,
t h e p r o d u c t s o b t a i n e d h y d r o g e n , m e t h a n e , and e t h a n e .
He
s u g g e s t e d t h a t s y m m e t r i c a l d i m e t h y l h y d r a z i n e was fo rm ed
a s an i n t e r m e d i a t e .
T r a v e r s Q 12 f o l l o w i n g t h e k i n e t i c s
o f d e c o m p o s i ti o n by a n a l y t i c a l m eth ods f i n d s t h a t
d i m e th y la m in e decom posed a t 4 2 0 ° y i e l d s m e th a n e , m e th y l
m e t h y l e n e im i n e a n d p r i m a r y m e t h y l a m in e , w i t h s m a l l
a m oun ts o f h y d r o g e n .
R ic e and J o h n s t o n ^
p a sse d th e
v a p o r s o f d im e th y la m in e and t r i m e t h y l a m i n e t h r o u g h s i l i c a
t u b e s a t 1000°C and w ere a b l e t o remove s t a n d a r d m i r r o r s o f
a n ti m o n y .
The d e c o m p o s i t i o n o f t r i m e t h y l a m i n e h a s b e en s t u d i e d
by T r a v e r s 9 »12 who f i n d s i t t o be som ewhat l e s s c o m p l i ­
c a t e d t h a n t h e p r i m a r y a n d s e c o n d a r y m e tliy la m in e s .
It
y i e l d s a s m ain p r o d u c t s m eth an e and m e t h y l m e t h y l e n e i m i n e .
He c o n c l u d e s t h a t t h e m eth an e i s fo rm e d fro m m e th y l r a d ­
i c a l s w h ic h a r e p r o d u c e d i n t h e p r i m a r y s p l i t .
H ydrogen
and e t h a n e w ere o b s e r v e d i n s m a l l a m o u n ts .
The k i n e t i c s o f d e c o m p o s i t i o n o f e t h y l a m i n e h a s
b e e n i n v e s t i g a t e d by T a y l o r 1 4 ,1 5 Wh 0 c o n c l u d e s t h a t t h e
r e a c t i o n p r o c e e d s by means o f d i e t h y l h y d r a z i n e an d h y d r o ­
g e n t o y i e l d n i t r o g e n , h y d r o g e n , m e t h a n e ,a n d u n s a t u r a t e d
h y d rocarbons.
T h ere i s some d i s a g r e e m e n t i n r e g a r d t o t h e
p r o d u c t s a s S chu m acher and W iig l b f i n d ammonia t o be
p r e s e n t , w i t h n i t r o g e n , h y d r o g e n , a n d m e th a n e .
In f u r t h e r s u p p o r t o f T a y l o r 's p o s t u l a t e d fo rm a tio n
o f d i e t h y l h y d r a z i n e , t h i s compound was p r e p a r e d an d p y r o l y s e d -*-5 and t h e p r o d u c t s a g r e e d w i t h t h o s e o b t a i n e d fro m
th e e th y lam in e i t s e l f .
R a m s p e rg e r 2 b , 2 7 ,2 8 p y r o l y s e d
a z o m e t h a n e , o b t a i n e d n i t r o g e n , e t h y l e n e , a n d m e th a n e .
The
d e c o m p o s i t i o n o f a z o - i s o p r o p a n e was a l s o e x a m in e d sh ow ing
th e fo rm a tio n o f n i tr o g e n and h y d ro c a rb o n s .
T h ese t e n d e d
t o i n d i c a t e t h a t h y d r a z i n e s o r a z o compounds a r e p r e s e n t
a s i n t e r m e d i a t e s i n t h e p y r o l y s i s o f t h e e t h y l a m i n e w here
n i t r o g e n i s found a s a p r o d u c t , in d i s t i n c t i o n to th e
o t h e r a m in e s w here ammonia i s u s u a l l y o b s e r v e d .
Upson
a nd S a n d s 17 c a r r i e d o u t a p y r o l y s i s on e t h y l a m i n e a t 5 0 0 ,
7 0 0 ° an d 1 000° i n t h e p r e s e n c e o f k a o l i n and o b t a i n e d
am m onia, h y d r o g e n c y a n i d e , a c e t o n i t r i l e , e t h y l e n e , a n d some
h y d ro g e n ,a n d n i t r o g e n .
H urd and C a r n a h a n
r e p o r t hydro­
g e n , and a c e t o n i t r i l e a s t h e m ain p r o d u c t s a t 5 0 0 ° .
The p h o t o l y s i s o f e t h y l a m i n e
h a s been r e ­
p o r t e d y i e l d i n g h y d r o g e n , m e th a n e , e t h a n e , a n d n i t r o g e n ,
an d a non v o l a t i t e
liq u id .
T a y l o r 2 0 ,2 1 k a s e x am in e d t h e d i e t h y l an d t r i e t h y l am ine and p o s t u l a t e t h e p r o b a b l e f o r m a t i o n o f a h y d r a z i n e
and b u t a n e , w i t h s u b s e q u e n t d e c o m p o s i t i o n o f t h e s e two p r o ­
d u c ts.
Upson an d S a n d s -*-7 s t u d i e d p r o p y l a m in e by a dynam ic
m etho d and f o u n d a n i t r i l e , h y d r o c a r b o n s , a m m o n ia ,h y d ro g e n
c y a n i d e ^ n i t r o g e n , and h y d r o g e n .
T a y l o r e x a m in e d t h e p r o p y l
a nd i s o p r o p y l a r a i n e by th e p r e s s u r e change m eth od an d fo u n d
t h e r e a c t i o n s t o be a p p a r e n t l y u n i m o l e c u l a r an d homo­
geneous.
S ickm an and R ic e 24 ^ so e x am in e d t h e decompo­
s i t i o n o f n -p ro p y la m in e .
They f o u n d t h a t no s a t i s f a c t o r y
e x p l a n a t i o n o f t h e c o u r s e o f t h i s r e a c t i o n c o u l d be o f f e r e d ,
b u t t h a t i t was a n a l o g o u s t o t h e c a s e o f e t h y l a m i n e a s d e -
-4 -
s c r i b e d by S chum acher and N i i g
No d a t a w ere fo u n d
On t h e p h o t o l y s i s o f p r o p y l a m i n e s .
Bamford
^5
h as s t u d i e d th e p h o t o l y t i c d e co m p o sitio n
o f a num ber o f a m in e s .
He c o n c l u d e s t h a t t h e p r i m a r y a c t
f o r n o r m a l and s e c o n d a r y a m in e s p r o d u c e s a h y d r o g e n ato m
an d a l k y l a m i n o r a d i c a l s .
F u r t h e r r e a c t i o n o f th e h y d ro ­
g e n atom w i t h am ine p r o d u c e s m o l e c u l a r
hyd ro g en .
The
a lk y la m in o r a d i c a l t h a t re m a in s , r e a c t s to g iv e a S c h i f f s
b a s e and s p l i t o f f an a l k y l g r o u p and a d i a l k y l a m i n o
r a d i c a l , b o t h o f w h ic h r e a c t f u r t h e r .
The p r e s e n c e o f
h y d r o g e n atom s was t e s t e d f o r by means o f p r o p y l e n e r e a
a c t io n , to fo rm ^ p ro p y l r a d i c a l , a n d c o m b in atio n to g iv e
hexane.
The a m in es s t u d i e d w ere d i - and t r i m e t h y l ^ n -
b u t y l a m i n e and n - a m y la m in e .
The n - b u t y l a m i n e y i e l d e d m a in ly h y d r o g e n , an d am­
m onia a s g a s e o u s p r o d u c t s , a n d s m a l l am o u n ts o f m eth ane,
and p r o p a n e .
No n i t r o g e n was e v e r d e t e c t e d i n t h e p h o t o ­
l y s i s o f n -b u ty la m in e .
The r a t i o o f h y d ro g e n t o ammonia
i s c o n s t a n t f o r d i f f e r e n t p e r i o d s o f i r r a d i a t i o n so t h a t
it
i s u n l i k e l y t h e r e i s any p h o t o l y s i s o f t h e ammonia.
A l i q u i d f r a c t i o n was o b t a i n e d w h ic h he was u n a b l e t o
id e n tify .
The p h o t o l y s i s o f n -a m y la m in e r e s e m b l e s t h a t o f
n -b u ty la m in e v e ry c l o s e l y .
In th e trim e th y la m in e th e
p r i m a r y a c t i s t o s p l i t o f f a m e t h y l r a d i c a l and g i v e a
d i m e t h y la m i n e r a d i c a l w h ic h r e a c t s t o g i v e s e c o n d a r y
m e th y la m in e a n d m e t h y l m e t h y l e n e i m i n e , w h ic h p o l y m e r i z e s .
I n a r e c e n t p a p e r by R i c e a n d T e l l e r
1 2 3
i t was
p o s t u l a t e d t h a t on t h e b a s i s o f t h e p r i n c i p l e o f l e a s t
m o tio n t h e d e c o m p o s i t i o n o f n - b u t y l a m i n e w ou ld y i e l d
e t h y l e n e , and ammonia a s p r o d u c t s .
by R ic e i s t h a t , t h e r e
The t h e o r y a s s t a t e d
s h a l l be t h e l e a s t c h an g e i n a to m ic
p o s i t i o n and t h e l e a s t c h an g e i n e l e c t r o n i c c o n f i g u r a t i o n
d u r i n g an e l e m e n t a r y r e a c t i o n .
S in c e th e en erg y o f a c t i ­
v a t i o n n e c e s s a r y t o b r i n g t h e a to m s fro m t h e i r o l d t o new
p o s i t i o n s h a l l be a s s m a l l as p o s s i b l e ,
r e a l i z e d when t h e r e i s a s l i t t l e
in g e n e ra l th is
is
m o tio n a s p o s s i b l e .
R ice r a i s e s th e q u e s tio n o f w h e th e r th e r m a l d eco m p o sitio n
o c cu r to g iv e th e p ro d u c t m o le c u le s in a s i n g l e a c t o r
w h e t h e r t h e r e a c t i o n p r o c e e d s t h r o u g h a c h a i n m echanism .
I n s u p p o r t o f t h e s e p o s t u l a t e s Rice-*- c i t e s t h e e x ­
am ple o f t h e p y r o g e n i c d e c o m p o s i t i o n o f n - p r o p y l a c e t a t e ,
2 9 ,3 0
a s w e l l a s s e v e r a l o t h e r s e s t e r s and a c e t a l s w h ic h have
been s t u d i e d e x p e r i m e n t a l ly .
In th e c a se o f th e n - p r o p y l ­
a c e t a t e , a c e tic a c id i s s p l i t o u t le a v in g p ro p y le n e .
The
a c e t a l g i v e s t h e a n h y d r i d e and a l d e h y d e on r e a c t i o n a t
h ig h te m p e ra tu re s.
F u r t i i e r e v i d e n c e i s t o be fo u n d i n t h e
p h o t o c h e m i c a l d e c o m p o s i t i o n o f n i t r i l e s 3 2 , 3 3 , 3 4 , 3 7 Wh e r e
a s p l i t i n t o NOH, and a ld e h y d e i s show n.
S t e a c i e 3 5 ,3 b
s u g g e s ts in th e th e rm a l d e c o m p o sitio n s t h a t th e r e a c t i o n
i s R - CH2 - 0 - N - 0 ------ * R - CH2 - 0 4 - NO.
A n o t h e r t y p e o f compound f o r w h ic h t h e p r o d u c t s o f t h e r m a l
-
6-
d e c o m p o s i t i o n w ere p o s t u l a t e d i s t h a t o f n - b u t y l , m e t h y l
e t h e r , w here t h e s p l i t i n t o m e t h y l a l c o h o l , a n d two m o le ­
c u l e s o f e t h y l e n e was e x p e c t e d .
experimentally,^
T h is h a s b e e n e x a m in e d
b u t no e v id e n c e f o r t h i s k in d o f r e a c ­
t i o n t a k i n g p l a c e was f o u n d .
The p u r p o s e f o r w h ic h t h i s r e s e a r c h was •u n d e rta k e n ,
was t o s t u d y t h e t h e r m a l d e c o m p o s i t i o n o f n - b u t y l a m i n e .
I n v ie w o f th e p o s t u l a t e o f R i c e 1 i n p r e d i c t i n g t h e p o s ­
s i b l e p r o d u c t s o f t h e p y r o l y s i s , q u i t e d i f f e r e n t from
t h o s e o f t h e lo w e r a m i n e s , i t was h o p e d t h a t a s i m p le
s p l i t w ould t a k e p l a c e , one m o le c u le o f amine y i e l d i n g
two m o l e c u l e s o f e t h y l e n e , and one m o le c u le o f amm onia.
The n - b u t y l a m i n e u s e d t h r o u g h o u t t h e s e e x p e r i m e n t s
was o b t a i n e d fro m E astm an Kodak Company.
On f r a c t i o n a l
d i s t i l l a t i o n ^ i t was fo u n d t o h a v e a b o i l i n g p o i n t r a n g e
o f 7 6 ° - 7 7° a t 755 mm. p r e s s u r e , n i n e t y p e r c e n t coming
o v e r b e tw ee n 7 5 . 4 - 7 b . 6 .
T h is f r a c t i o n was t a k e n and
t h e m id d le t h i r d b o i l i n g i n r a n g e 7 b . 5 - 7 b . b ° was u s e d
in a l l o f th e fo llo w in g e x p e rim e n ts .
P art I .
A p p a ratu s and P ro c e d u re
A. S t a t i c E x p e r i m e n t s .
A Pyrex g l a s s r e a c t i o n f l a s k tw e n ty - f iv e c e n tim e te r s
l o n g h a n d e i g h t c e n t i m e t e r s i n d i a m e t e r h a v i n g an e s t i m a t e d
volum e o f t w e lv e h u n d r e d c u b ic c e n t i m e t e r s , w a s u s e d f o r
th e se e x p erim e n ts.
The f l a s k was c o n s t r u c t e d w i t h a d e ep
t h e r m o m e te r w e l l p r o j e c t i n g i n t o t h e c e n t e r o f t h e v e s s e l .
The t e m p e r a t u r e was m e a s u re d by means o f p l a t i n i u m r e s i s ­
t a n c e th e r m o m e te r , whose r e s i s t a n c e e le m e n t was p l a c e d i n
th e w e ll o f th e r e a c tio n f l a s k .
The v e s s e l was pumped
o u t by means o f a s i n g l e s t a g e m e r c u ry d i f f u s i o n pump
b a c k e d by a Cenco Hyvae o i l pump.
The n - b u t y l a m i n e was
s t o r e d i n a t r a p c o n t a i n i n g a b o u t f i f t y c u b ic c e n t i m e t e r s
of liq u id .
T h i s was f r o z e n i n a s o l i d c a r b o n d i o x i d e and
t o l u e n e m i x t u r e and e v a c u a t e d .
Betw een t h e n - b u t y l a m i n e s t o r a g e v e s s e l and t h e r e ­
a c t i o n cham ber was a one l i t r e
P y re x f l a s k , i n t o w h ic h t h e
8-
n - b u t y l a m i n e was d i s t i l l e d .
The l a r g e v e s s e l was t h e n
c l o s e d o f f and h e a t e d t o 5 0 ° t o v a p o r i z e t h e l i q u i d w h ic h
had condensed.
F r a c t i o n s o f t h i s g a s c o u l d t h e n be a d ­
m i t t e d t o t h e r e a c t i o n v e s s e l i t s e l f , t o g i v e any d e s i r e d
i n i t i a l p re s s u re o f b u ty la m in e .
The r e a c t i o n p r o d u c t s
w ere t h e n pumped o u t by means o f a T o e p l e r pump t h r o u g h
a tr a p c o n ta in in g l iq u id n itr o g e n .
The c o n n e c t i n g t u b i n g u s e d t h r o u g h o u t c o n s i s t e d o f
two mm. i n t e r n a l d i a m e t e r P y r e x g l a s s .
The e s t i m a t e d
d e a d s p a c e o u t s i d e t h e f u r n a c e was a b o u t t w e n t y - f o u r c u ­
b i c c e n t i m e t e r s o r a b o u t two p e r c e n t o f t h e volume o f th e
re a c tio n fla s k .
I t was fo u n d n e c e s s a r y t o h e a t a l l c o n ­
n e c t i n g t u b i n g t o p r e v e n t l i q u e f a c a t i o n o f t h e a m in e j
w h ic h h a s a v a p o r p r e s s u r e o f a b o u t one h u n d r e d mms. a t
room t e m p e r a t u r e s .
T h is was done by w ra p p in g t h e s y s te m
o u t s i d e t h e f u r n a c e w i t h N ichrom e w i r e , B a n d S g a u g e 3 0 ,
a n d p a s s i n g o n e - h a l f an am pere t h r o u g h i t .
The p r e s s u r e was m e a s u re d by a c o n s t a n t volume
m e rc u r y m an o m ete r, so t h a t t h e r e w ould be no i n c r e a s e i n
th e dead space as a r e a c t i o n p ro c e e d e d .
The t u b i n g was
one c e n t i m e t e r i n d i a m e t e r t o e l i m i n a t e c a p i l l a r y e f f e c t s .
The f u r n a c e was made o f a s e c t i o n o f f o u r i n c h p i p e ,
w ra p p e d w i t h a s b e s t o s p a p e r , an d wound w i t h h e a v y ITichrome
rib b o n .
The w hole u n i t was p a c k e d i n a l a r g e r c o n t a i n e r
w i t h a s b e s t o s , and g l a s s w ool, t o m in im iz e a n y h e a t l o s s ,
and b r i n g t h e t e m p e r a t u r e f l u c t u a t i o n t o a s s m a l l a v a l u e
-9 -
as p o s s ib le .
A c u r r e n t o f t h r e e t o t h r e e and o n e - h a l f
a m p e re s w ere u s e d t o m a i n t a i n t h e t e m p e r a t u r e a t 5 0 0 °•
The c u r r e n t was a d j u s t e d by means o f a v a r i a b l e r e s i s ­
ta n c e .
I n m aking a r u n , b u t y l a m i n e i n t h e s t o r a g e v e s s e l
was f r o z e n i n c a r b o n d i o x i d e t o l u e n e , and t h e w hole s y s ­
tem e v a c u a t e d .
B e f o r e t h e am ine was u s e d , i t was a l l o w e d
t o r e a c h room t e m p e r a t u r e u n d e r vacuum^ a n d e x p a n d i n t o
th e l i t r e
b u l b , b u t n o t i n t o t h e r e s t o f t h e s y s t e m , and
i t was f r o z e n a g a i n .
Any r e s i d u a l p e rm a n e n t g a s e s , t h a t
may h a v e b e e n i n t h e a m i n e , a r e t h u s rem oved on s u b s e q u e n t
pu m p ing .
The am ine was now b r o u g h t t o room t e m p e r a t u r e , o r
s l i g h t l y abo ve and f i l l e d
th e l i t r e
b u l b , w h i c h was c o o l e d
s o m e w h a t,s o t h a t amine c o n d e n s e d o u t i n i t .
The l i t r e
b u l b was t h e n s h u t o f f fro m t h e am ine t r a p , a n d t h e tem ­
p e ra tu re r a is e d to 50°.
The am ine was t h e n a d m i t t e d i n t o
th e r e a c t i o n s y s te m ,to g iv e th e d e s ir e d p r e s s u r e .
The
tim e was t a k e n by means o f a s t o p w a t c h , a s so o n a s p o s ­
s i b l e a f t e r c lo s in g th e s to p c o c k ,a n d th e p r e s s u r e re a d
a t t h e same tim e on t h e m a n o m e te r.
tim e v/ere r e a d a t d e f i n i t e
The p r e s s u r e and
i n t e r v a l s , over th e p e rio d o f
an h o u r , and i n some c a s e s f o r a p e r i o d o f s i x h o u r s .
The s y s te m was t h e n o p e n e d t o t h e t r a p c o o l e d i n l i q u i d
n i t r o g e n , a n d t h e p e rm a n e n t g a s e s c o u l d be draw n o f f .
10
B. D ynam ic>
The dynam ic s y s te m c o n s i s t e d i n p a r t o f a h o r i ­
z o n ta l e le c t r i c
in g 1 0 0 0 ° .
f u r n a c e , 30 cms lo n g c a p a b l e o f r e a c h ­
T h ro u g h t h e f u r n a c e r a n a q u a r t z t u b e o f
f i v e m il l im e te r s i n t e r n a l d ia m e te r,;c o n n e c te d a t e i t h e r
end to P y re x ,b y g rad ed s e a l s .
w i t h a g ro u n d g l a s s j o i n t .
The e n t r a n c e was f i t t e d
The b u t y l a m i n e was p l a c e d
in a f i f t y c u b ic c e n tim e te r f l a s k s e a le d to t h i s j o i n t ,
s o t h a t i t c o u l d be r e m o v e d ,a n d w e i g h t e d .
At th e o th e r
e n d o f t h e q u a r t z t u b e w ere s e a l e d two re m o v e a b le t r a p s ,
c o n n e c te d to a f i v e l i t r e
r o u n d b o tto m f l a s k .
The w hole
s y s t e m was pumped o u t by a s i n g l e s t a g e m e r c u ry d i f f u ­
sio n - pump, b a c k e d by a Cenco Hyvac o i l pump.
The p r e s ­
s u r e i n t h e s y s te m c o u l d be m e a s u r e d by means o f a m er­
c u r y m a n o m e te r.
The g a s e s fo rm e d d u r i n g a r u n w ere
pumped o u t by means o f a l i t r e
T o e p l e r pumpf c o n n e c t e d
w ith a gas a n a ly s e r.
I n m aking a r u n , n - b u t y l a m i n e was w e ig h e d o u t i n t o
t h e 50 c c s . b u l b , f r o z e n i n c a r b o n d i o x i d e t o l u e n e , and
p u t in th e a p p a r a tu s .
and t h e
The w hole s y s te m was e v a c u a t e d ,
b u t y l a m in e , m e l t e d , a n d r e f r o z e n t o i n s u r e t h a t
a l l o x y g en was rem oved b e f o r e a r u n was s t a r t e d .
The
s i l i c a t u b e was t h e n r a i s e d t o 9 5 0 ° , a n d m a i n t a i n e d a t
t h a t t e m p e r a t u r e f o r a tim e w i t h t h e vacuum pump r u n n i n g .
The t e m p e r a t u r e o f t h e f u r n a c e was m a i n t a i n e d by a n
A d j u s t - A ^ V o l t v a r i a b l e t r a n s f o r m e r , w h ic h was f o u n d
11
sa tis fa c to ry .
vacuum l i n e .
The s y s te m was now s h u t o f f fro m t h e
The d r y i c e t o l u e n e was rem oved fro m t h e
b u t y l a m i n e , and a b e a k e r o f warm w a t e r p l a c e d a r o u n d t h e
am ine v e s s e l t o b r i n g t h e am ine t o room t e m p e r a t u r e a s
ra p id ly as p o s s ib le .
D e p e n d in g upon t h e t e m p e r a t u r e o f
t h e b a t h ^ t h e r a t e o f f l o w c o u l d be c o n t r o l l e d .
L iq u id
n i t r o g e n was p l a c e d a ro u n d t h e t r a p s a t t h e e x i t e n d o f
th e fu rn a c e to condense e v e r y th in g b u t th e perm an en t
g a s e s j w h i c h were a ll o w e d t o e x p a n d i n t o t h e f i v e l i t r e
b u lb > w h ic h had b e e n e v a c u a t e d .
At th e c o n c lu sio n o f a
r u n , t h e p e rm a n e n t g a s e s w ere pumped o f f by means o f
th e T o e p le r,a n d a n a ly z e d .
When no more g a s c o u l d be
w ith d ra w n t h e l i q u i d n i t r o g e n was re m o v e d ,
A mush o f
s e c - b u t y l . c h l o r i d e , w h ic h h a d b e e n c o o l e d w i t h l i q u i d
n i t r o g e n t o - 1 3 1 ° was p l a c e d a ro u n d t h e traps^, an d a g a i n
t h e g a s c o m p l e t e l y re m o v e d .
T h is was r e p e a t e d w i t h a
b a t h o f c a r b o n d i o x i d e and t o l u e n e .
The g a s e s o b t a i n e d ab o v e w ere m e a s u re d i n a one
h u n d r e d c c s . b u r e t t e f i l l e d w i t h d r y m e rc u ry , a n d p a s s e d
i n t o an O r s a t F i s h e r u n i t i z e d t e c h n i c a l g a s a n a l y s e r .
As o n l y h y d r o g e n and m eth an e w ere f o u n d i n t h e f r a c t i o n
fro m l i q u i d n i t r o g e n , t h e s e w ere d e t e r m i n e d by c o m p le te
o x i d a t i o n i n t h e slo w c o m b u s tio n p i p e t t e , b u r n t i n t h e
p r e s e n c e o f a h o t p l a t i n i u m wire^ i n e x c e s s o x y g e n .
From t h e amount o f c o n t r a c t i o n , a n d am ount o f c a r b o n
d i o x i d e f o r m e d , t h e p e r c e n t a g e h y d ro g e n , a n d c a r b o n d i o x i d e
-1 2 -
may be c a l c u l a t e d #
The n e x t , f r a c t i o n from s e c o n d a r y
b u t y l c h l o r i d e c o n t a i n e d u n s a t u r a t e d , an d s a t u r a t e d h y ­
d ro carb o n s#
A c e t y l e n e s w ere rem oved i n a t w o - t e n t h s
n o r m a l a m m o n iac al s i l v e r n i t r a t e
so lu tio n ,
in a b u b b le r
p i p e t t e , t h e ammonia b e i n g rem oved by d i l u t e s u l p h u r i c
a c i d b e f o r e t h e c o n t r a c t i o n was m e a s u r e d .
The o t h e r u n ­
s a t u r a t e d compounds w ere a b s o r b e d i n a t w e n ty p e r c e n t
fu m ing s u l p h u r i c a c i d c o n t a c t p i p e t t e .
The r e m a i n i n g
s a t u r a t e d h y d r o c a r b o n s were b u r n e d i n t h e slo w combus­
t io n p i p e t t e as d e sc rib e d above.
The f r a c t i o n fro m d r y
i c e t o l u e n e was p a s s e d i n t o a t e n p e r c e n t s u l p h u r i c a c i d
s o l u t i o n t o a b s o r b am m o n ia,an d t h e r e m a i n d e r t r e a t e d a s
above.
The c a r b o n d i o x i d e was rem oved i n a b u b b l e r p i ­
p e t t e c o n ta in in g a f i f t y p e rc e n t s o lu tio n o f p o tassiu m
h y d ro x id e.
Oxygen c o u l d be a b s o r b e d i n a b u b b l e r p i ­
p e tte c o n ta in in g a lk a lin e p y r o g a llo l.
P art I I .
E x p e rim e n ta l D a ta
The i n c r e a s e i n p r e s s u r e i n t h e s y s te m due t o t h e
d e c o m p o s i t i o n o f b u t y l a m i n e i s shown i n g r a p h s I - IV.
In th e s e th e in c r e a s e o f p re s s u re , o v e r th e i n i t i a l p r e s s u r e i s p l o t t e d a g a i n s t t h e tim e i n m i n u t e s .
s e t o f d a t a i s p r e s e n t e d b e lo w .
A ty p ic a l
MZO
■
P d C H n a i a K H
61< i
0
4
e
12
18
20
24
28
32
3C
Graph I
40
44
48
62
66 00
MI2J,
to°c
Til'.
i:.
i:
Graph I I
*5
44
*3
42
41
40
39
38
3T
3*
35
3*
33
32
31
30
29
28
27
26
25
24
23
22
21
20
19
13
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
-S3£
n*
Graph I I I
2 4 ,0
C
O
o
CO
H isu
<H!E
oo
*
Graph IV
rH
o
13-
T a b le 1 .
T e m p e r a tu r e
Tlme
0 m in .
2
3
4
5
o
7
8
9
15
21
30
40
50
60
Time
0 m in .
2
4
o
8
10
20
30
40
50
DO
Time
0 m in .
2
4
6
8
10
20
30
40
50
60
530°C .
P ressure
1 0 . 8 cm s. 0 . 0
1 2 .5
1 3 .3
1 4 .1
1 4 .8
1 5 .5
1 6 .1
1 6 .7
1 7 .3
2 0 .1
2 1 .9
2 3 .5
2 4 .6
25*3
2 5 .8
P ressure
AP
cm s.
1 .7
2 .5
3 .3
4 .0
4 .7
5 .3
5 .9
6 .5
9 .3
1 1 .1
1 2 .7
1 3 .8
1 4 .5
1 5 .0
AP
7 . 6 cm s. 0 . 0 cms.
8 .7
1 .1
9 .8
2 .2
1 0 .7
3 .1
1 1 .5
3 .9
1 2 .3
4 .7
1 4 .8
7 .2
1 6 .3
8 .7
1 7 .2
9 .6
1 7 .8
1 0 .2
1 8 .2
1 0 .6
P ressure
1 5 .0 cms.
1 7 .9
2 0 .3
2 2 .3
2 4 .0
2 5 .4
2 9 .9
3 2 .0
3 3 .2
3 4 .0
3 4 .4
AP
0 . 0 eras.
2 .9
5 .3
7 .3
9 .0
1 0 .4
1 4 .9
1 7 .0
1 8 .2
1 9 .0
1 9 .4
k x 10 "3
— secs7^
1 .2 3
1 .1 5
1 .0 9
1 .0 5
1 .0 1
0*95
0 .9 1
0 .8 7
o*o9
0 .5 6
0 .4 3
0 .3 4
0 .2 9
0 .2 4
k x 10 “3
— secs?1
1 .1 3
1 .1 1
0 .9 5
0 .8 6
0 .8 0
0 .5 5
0 .4 3
0 .3 4
0 .2 8
0 .2 4
k x 10~5
— secs?1
1 .4 5
1 .2 5
1.10
0 .9 8
0.88
0 .5 7
0 .4 2
0 .5 3
0.2S
0 .2 4
14T e m p e r a tu re 5 3 0 °C .
Time
0 m in .
2
4
8
10
20
30
40
50
60
P ressu re
2 1 . 0 cms.
2 4 .9
2 8 .5
3 4 .0
3o . 2
4 2 .7
4 5 .7
4 7 .3
4 8 .1
4 8 .6
AP
0.0
3 .9
7 .5
1 3 .0
1 5 .2
2 1 .7
2 4 .7
2 b .5
2 7 .1
2 7 .6
k x 10"3
— s e c s :- 1
1 .3 8
1 .2 8
1 .0 0
0 .9 1
0 .5 9
0 .4 5
0 .3 4
0 .2 8
0 .2 3
T e m p e r a tu r e 5 2 0 °C •
Time
0 m in .
2
6
8
10
20
30
40
50
60
Time
0
4
b
8
10
20
30
40
50
60
Time
0
4
b
8
10
20
30
40
50
oO
P ressu re
6 , 8 cms.
7 .3
8 .3
8 .8
9 .5
1 1 .4
1 3 .0
1 4 .0
1 4 .8
1 5 .3
P ressure
1 0 .7
12.2
1 3 .0
1 3 .8
1 4 .6
1 8 .0
20.2
21.8
2 2 .9
2 3 .8
P ressure
15 . b
1 8 .3
1 9 .8
21.2
22.6
2 7 .6
3 0 .8
3 2 .9
3 4 .3
3 5 .3
£1
0.0
0 .5
1 .5
2.0
2 .5
4 .6
6.2
7 .2
8.0
8 .5
AP
0.0
1 .5
2 .3
3 .1
3 .9
7 .3
9 .5
11.1
12.2
1 3 .1
AP
0.0
2 .7
4 .2
5 .6
7 .0
12.0
1 5 .2
1 7 .3
1 8 .7
1 9 .7
k x 10“4
-1
*■w B 6 C S|
5 .2
5 .5
5 .3
5 .2
4 .3
3 .6
3 .0
2.6
2 .3
k x 10“4
5 .5
5 .4
5 .3
5 .2
4 .3
3 .5
3 .0
2 .5
2.2
k x 10 “4
6 .5
b .b
6 .4
6.2
4 .8
3 .8
2.8
2 .5
2 .3
-1 5
T e m p e r a tu r e 520 °C .
P ressure
Time
0 m in .
4
6
8
10
20
30
40
50
60
2 2 , 0 cms *
2 6 ,4
2 9 .0
3 1 .8
3 4 .3
4 2 .6
4 6 .5
4 8 .4
4 9 .7
5 0 .3
At
k x 10"4
0 . 0 cms.
4 .4
7 .0
9 .8
1 2 .3
20 . b
2 4 .5
2 6 .4
2 7 .7
2 8 .3
— se c s-1
7 .6
7 .6
7 .5
7 .4
5 .5
4 .2
3 .3
2 .7
2 .5
T e m p e r a tu r e 510°C
Time
0
4
6
8
10
20
30
40
50
60
Time
0
4
6
8
10
20
30
40
50
bO
P ressure
1 9 .5
21.0
22.1
2 3 .3
2 4 .5
3 0 .2
3 4 .4
3 7 .1
3 9 .2
4 0 .6
P ressure
9 .b
10.2
10.6
11.0
1 1 .4
1 3 .5
1 5 .3
lb . 8
1 8 .0
1 9 .0
At
0 .0
1 .7
2 .8
4 .0
5 .2
1 0 .9
1 5 .1
1 7 .8
1 9 .9
2 1 .3
At
0.0
O .b
1.0
1 .4
1.8
3 .9
5 .7
7 .2
8 .4
9 .4
k x 10~4
MM
3 .5
3 .8
3 .9
3 .9
3 .7
3 .2
2 .6
2 .4
2 .1
k x 10“4
MM
2 .4
2 .8
2 .9
2 .9
2.8
2 .6
2 .3
2.1
1 .9
To o b t a i n t h e i n i t i a l r a t e o f r e a c t i o n , t h e l o g a r i t h m
o f t h e p r e s s u r e i s p l o t t e d a g a i n s t t h e tim e i n s e c o n d s ,
a n d t h e s l o p e a t z e r o tim e f o u n d .
The v a l u e o f t h e r a t e
t h u s o b t a i n e d i s p r e s e n t e d i n T a b le 2 f o r t h e t h r e e
-1 6 -
t e m p e r a t u r e s 5 3 0 ° , 5 2 0 ° , 5 1 0 °C .
The r a t e s o f r e a c t i o n
g i v e n i n T a b le 1 a r e t h o s e c a l c u l a t e d fro m t h e g e n e r a l
r a t e e q u a t i o n , w here t h e p r e s s u r e r a t i o
i s assu m ed t o
r e p r e s e n t t h e c o n c e n t r a t i o n o f b u t y l a m i n e w h ic h h a s d e ­
com posed, t o t h a t w h ic h r e m a in s u n c h a n g e d a t t h e en d o f
a g i v e n tim e*
The i n i t i a l r a t e a p p e a r s t o be d e p e n d e n t upon t h e
i n i t i a l p r e s s u r e o f am ine, a s i n a l l c a s e s t h e r e
is a
m arked i n c r e a s e i n t h e r a t e a s t h e i n i t i a l p r e s s u r e o f
am ine i n c r e a s e s *
Thus i t d o e s n o t seem t h a t t h e decom­
p o s i t i o n c a n be o f f i r s t o r d e r , a t t h e s e t e m p e r a t u r e s , and
a t t h e p r e s s u r e s used*
From t h e i n i t i a l r a t e s o f r e a c t i o n , a p l o t o f t h e
lo g a r ith m o f th e r a t e a g a i n s t th e r e c i p r o c a l o f th e ab ­
s o l u t e te m p e r a tu re , a v a lu e o f th e a c t i v a t i o n e n e rg y i s
o b ta in e d .
T h is was fo u n d t o be a b o u t 89 K. c a l ^ a n d
d o u b t l e s s i s to o l a r g e a v a l u e f o r a s i n g l e s im p le r e ­
a c tio n .
I t s e r v e s t o i n d i c a t e t h a t t h e d e c o m p o s i ti o n
i s c o m p le x ,e v e n a t low p r e s s u r e s , a s t h e r a t e s u s e d i n
t h e c a l c u l a t i o n w ere t h o s e a t z e r o tim e fro m t h e l o g ­
a r i t h m , tim e p l o t *
I t w ould a p p e a r t h a t a t l e a s t two
sim u lta n e o u s r e a c t i o n s s e t in t o g e t h e r , o r t h a t th e p ro ­
d u c t s fro m t h e i n i t i a l s p l i t a r e v e r y u n s t a b l e t h e r m a l l y .
Gas a n a l y s i s upon t h e r e s i d u a l g a s e s a t t h e e n d o f
an h o u r ' s d e c o m p o s i t i o n a l s o i n d i c a t e d t h a t ^ t h e r e a c t i o n
was c o m p l i c a t e d , a s a w ide v a r i e t y o f p r o d u c t s w ere found*
-1 7 -
I n t h e dynam ic s e t up t o be d i s c u s s e d t h e s e w i l l be g i v e n
in d e t a i l ,
A r e p r e s e n ta tiv e a n a ly s is o f th e s t a t i c p ro ­
d u c ts g iv e s
22.0% h y d r o g e n ,
1 9 . 6 ^ m e th a n e , 3 0 .2 ^ e t h y l e n e
15*0/o e t h a n e an d 1 2 .1 ^ ammonia.
Owing t o t h e s m a l l n e s s
o f t h e sa m p le s i t i s d i f f i c u l t t o be s u r e i f n i t r o g e n i s
p r e s e n t ^ b u t t h e a n a l y s i s on t h e p r o d u c t s o f p y r o l y s i s i n
t h e dynam ic e x p e r im e n ts ^ show n i t r o g e n t o be a b s e n t .
T a b le 2 ,
T e m p e r a tu r e 5 30°C .
P ressure
2 4 .0 cms
2 1 .0
1 5 .0
1 2 .4
1 0 .8
7 .6
b .5
3 .5
S lo p e
k x 10 - 5 sec"^-
.3 1 0
• 260
.2 6 0
.2 3 6
.2 1 7
.2 0 4
.2 0 2
.1 9 6
1 .6 6
1 .5 3
1 .4 2
1 .3 4
1 .2 8
1 .2 0
1 .1 5
1 .1 5
T e m p e r a tu re 52 0°C .
P ressure
2 2 .0 cms
2 0 .7
lb .4
1 5 .6
1 2 .5
1 0 .7
6 .8
4 .1
S lo p e
. 133
.1 2 7
.1 2 7
.1 1 4
.0 9 8
.0 9 7
.0 9 7
.0 9 7
2 1 .7
1 9 .3
1 4 .8
S lo p e
.0 7 0
.0 b 7
.0 5 5
7 .6 6
7 .3 1
7 .3 1
6 .5 6
5 .b 4
5 .5 8
5 .5 8
5 .5 8
.
o
o
o
1—
1
T e m p e r a tu re
P ressu re
k x 10"4 s e c - 1
k x 10“ 4 s e c “ l
4 .0 3
3 .8 6
3 .1 7
-1 8 -
P ressure
T e m p e r a tu r e 510°C .
( c o n t ‘d)
S lo p e
k x 10~^seC~^
1 1 .7
9 .6
5 .8
4 .5
.0 5 0
.0 4 9
.0 4 9
.0 4 9
2 .8 8
2 .8 2
2 .8 2
2 .8 2
B. D ynam ic.
The p e rm a n e n t g a s e s w ere drawn o f f l i q u i d n i t r o g e n
a n d a n a l y s e d by c o m b u s tio n i n e x c e s s o f oxygen^ a s p r e ­
v i o u s l y d e s c r ib e d in th e e x p e r im e n ta l p a r t .
num ber s i x a s r e p r e s e n t a t i v e ,
T a k in g r u n
th e fo llo w in g a re th e r e ­
s u l t s o b ta in e d .
T a b le 3 .
Volume o f
e a s ta k e n
3 6 .4
5 5 .0
3 4 .6
9 .6
1 3 5 .8
Oxygen
Used
Oxygen
C a lc .
4 1 .2
6 4 .2
3 7 .4
1 0 .4
1 5 3 .2
4 2 .0
6 5 .0
3 7 .2
1 0 .7
1 5 4 .9
T o ta l
C02
C o n t r a c t i o n (CH4)
61.2
9 5 .0
5 8 .8
1 6 .2
2 3 1 .2
1 6 .2
2 5 .0
1 3 .2
4 .0
5 8 .4
h2
C a lc
1 9 .2
3 0 .0
21.6
5 .4
7 6 .2
The t o t a l am ount o f oxygen t a k e n was 1 9 9 .8 c c s .
and a r e s i d u a l o f 4 6 .0 c c s . re m a in e d .
T h i s was a b s o r b e d
in a l k a l i n e p y r o g a l l o l,a n d th e u n ab so rb ed gas t o t a l e d
4 .0
ccs.
A sa m p le o f t h e oxygen was a n a l y s e d j 5 0 . 0 c c s .
o f gas t a k e n , l e f t 1 .0 ccs^ u n a b so rb ed * th a t i s n itr o g e n .
The 4 . 0 c c s , u n a b s o r b e d , c a n t h u s be a c c o u n t e d f o r a s
n i t r o g e n in tr o d u c e d w ith th e oxygen.
T h i s was t h e c a s e
-1 9 -
in a l l o f th e a n a l y s i s o f th e d e c o m p o sitio n o f n - b u t y l a m i n e , t h a t a t no tim e was t h e r e any e v i d e n c e f o r n i t r o ­
gen i n t h e p e rm a n e n t g a s .
The f r a c t i o n draw n o f f s e c o n ­
d a r y b u t y l c h l o r i d e a t ~131°C. c o n s i s t e d o f some a c e t y l e n e ,
a l a r g e am ount o f e t h y l e n e , some e t h a n e , a s m a l l am ount o f
p r o p a n e , an d a s m a l l r e s i d u a l o f m e th a n e .
The g a s fro m s o l i d c a r t o n d i o x i d e to lu e n e a t -79°C
was made up o f a c o n s i d e r a b l e am ount o f amm onia, w i t h s m a l l
a m o u n ts o f u n s a t u r a t e d , a n d s a t u r a t e d h y d r o c a r b o n s .
The t o t a l volum e o f g a s pumped o f f was m e a s u re d
be 3 9 8 .6 c c s t o t a l l i n g
th e t h r e e f r a c t i o n s .
to
T h is was com­
p r i s e d o f 7 6 .2 c c s o f h y d ro g e n o r 1 9 .1 ^ o f t h e t o t a l , 7 1 .0
c c s o f m eth ane o r 17.8/o, 7 .2 c c s o f a c e t y l e n e s o r 1 .8 / i,
1 6 5 .3 c c s o f e t h y l e n e o r 4 1 . 5 ^ , 1 7 .3 c c s o f e t h a n e o r 4 . 3 ^ ,
4 . 1 c c s o f p r o p a n e o r l . C ^ and 5 4 .2 c c s o f ammonia o r 1 3 . 6 ^ .
To pump t h e l a s t o f t h e ammonia o f f i t was a lw a y s fo u n d
n e c e s s a r y t o a l l o w t h e r e s i d u a l b u t y la m in e t o l i q u e f y , and
th e n r e p la c e th e dry ic e to lu e n e b a th f o r s e v e r a l h o u rs to
e n s u r e t h a t t h e amine was c o m p l e t e l y f r o z e n o u t a g a i n .
"rh e n t h i s was done a b o u t o n e - f o u r t h o f t h e t o t a l ammonia
was o b t a i n e d .
E x p e r i m e n t s show ed t h a t once was s u f f i c i e n t ,
a s o n l y m in o r t r a c e s c o u ld be pumped o f f by t h e T o e p l e r
pump upon r e p e a t i n g t h e o p e r a t i o n .
A summary o f t h e r u n s may be s e e n i n T ab le 4 .
In
g e n e r a l t h e r e i s no v e r y m arked c h an g e i n t h e p r o d u c t s
o v e r r a t h e r w i d e l y v a r i e d c o n d i t i o n s o f t e m p e r a t u r e , and
-2 0 -
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-2 1
ra te
o f flo w .
The f o r m u l a , w h ic h i s o b t a i n e d by c a l c u l a t i n g t h e
w e i g h t o f e a c h e l e m e n t r e p r e s e n t e d i n t h e v a r i o u s com­
p o u n d s , summing t h e s e , a n d d i v i d i n g by t h e a to m ic w e i g h t .
The f o r m u la t h u s o b t a i n e d i s m u l t i p l i e d by a f a c t o r , s u c h
t h a t t h e c a r b o n v a l u e w i l l be f o u r j i n o r d e r t o o b t a i n a
c o m p a ris o n t o n - b u t y l a m i n e .
T h is s h o w s ,th a t o n ly a b o u t
f i f t y p e rc e n t o f th e o r i g i n a l n itr o g e n i s p r e s e n t in th e
g a s p h a s e , a t th e c o n c l u s i o n o f a r u n .
An e x a m i n a t i o n o f t h e l i q u i d f r a c t i o n was u n d e r ­
tak e n .
I t was p o s s i b l e t o o b t a i n a p r e c i p i t a t e o f s i l v e r
c y a n i d e , by n e u t r a l i z i n g t h e am ine r e s i d u e a t low t e m p e r a ­
t u r e s , w ith d i l u t e n i t r i c
a c i d an d a d d in g s i l v e r n i t r a t e .
The q u a n t i t y was n o t l a r g e and w ould r e p r e s e n t o n l y a b o u t
two p e r c e n t o f t h e g a s p h a s e .
The p r e c i p i t a t e was t a k e n ,
w e ig h e d and i g n i t e d i n a w e ig h e d c r u c i b l e , a t 500° i n an
a tm o s p h e r e o f n i t r o g e n .
The w e i g h t o f t h e s i l v e r b u t t o n
l e f t , s h o w e d t h a t th e compound was s i l v e r c y a n i d e .
I f t h e e x c e s s o f n - b u t y l a m i n e was d i s t i l l e d o u t o f
t h e l i q u i d f r a c t i o n , a s u b s t a n c e b o i l i n g a t a b o u t 160° was
o b tain ed .
T h is w ould r e d u c e a m m o n iac al s i l v e r n i t r a t e
t h e c o l d , and h a d a f r a g r a n t O d e r.
in
A m ic ro -K je ld a h l,
w h ic h was p r e f o r m e d on i t gave a v a l u e o f
30*1% n i t r o g e n .
The s u b s t a n c e h a s b e en t e n t a t i v e l y i d e n t i f i e d a s m e t h y l m e t h y l e n e i m i n e , w h ic h a s a n i t r o g e n v a l u e o f 3 2 . 6 ^ .
A
s l i g h t l y low v a l u e o f t h e n i t r o g e n w ould be p o s s i b l e a s
-2 2 -
it
i s v e r y d i f f i c u l t t o rem ove t h e b u t y la m in e fro m t h i s
s u b s t a n c e , a s t h e r e a r e v i s c o u s p o ly m e r s form ed by t h e
im in e upon h e a t i n g .
T h e re was some e v i d e n c e f o r th e
p re s e n c e o f d ib u ty la m in e in th e l i q u i d f r a c t i o n , a l t h o u g h
i t v/as n o t i s o l a t e d o r i d e n t i f i e d .
DISCUSSION
From an e x a m i n a t i o n o f t h e p r o d u c t s o f t h e dynamic
p y r o l y s i s , i t w ould seem t h a t t h e r e a c t i o n c a n n o t be s i m p l e .
I t may be p o s s i b l e t h a t ^ t h e i n i t i a l s p l i t i n v o l v e s a s i n g l e
r e a c t i o n , a n d t h e p r o d u c t s w h ic h a r e fo rm ed, a r e im m e d ia te l y
u n s t a b l e a t t h e t e m p e r a t u r e a t w h ic h t h e s e e x p e r i m e n t s
w ere c o n d u c t e d .
ered ,
A se c o n d p o s s i b i l i t y t h a t can be c o n s i d ­
i s t h a t two s i m u l t a n e o u s r e a c t i o n s t a k e p l a c e , b o t h
h a v i n g a b o u t t h e same e n e r g i e s o f . a c t i v a t i o n .
As b o t h
t h e dynam ic a n d s t a t i c m ethods y i e l d a b o u t t h e same t y p e
o f r e a c t i o n p r o d u c t s , i t w ould seem t h a t i f t h e f i r s t
is
t h e c a s e , t h e n t h e i n i t i a l r a t e s o f r e a c t i o n s h o u l d be
l e s s c o m p l i c a t e d and a r e a s o n a b l e e n e r g y o f a c t i v a t i o n
o b ta in e d .
The l a r g e v a r i e t y o f s u b s t a n c e s o b t a i n e d i n d i c a t e s
t h a t p o s s i b l y t h e l a t t e r w ould be a b e t t e r e x p l a n a t i o n
f o r w h at t a k e s p l a c e .
The f a c t t h a t no n i t r o g e n was e v e r fo u n d a s one o f
t h e p r o d u c t s w ould l e a d one t o r u l e o u t t h e p o s s i b i l i t y o f
an y h y d r a z i n e 15 f o r m a t i o n a l t h o u g h t h e l i q u i d f r a c t i o n i s
c a p a b l e o f r e d u c i n g am m o n iacal s i l v e r n i t r a t e .
T h is a c t i o n
was f o u n d t o be due t o a n o t h e r s u b s t a n c e , p o s s i b l y m e th y l
me t h y l e n e i m i n e .
B a n fo rd i n h i s s t u d y o f th e p h o t o l y s i s o f n - b u t y l a m in e ,c o n c lu d e s th e f o llo w in g i t h a t th e r a t i o o f hydrogen
24
t o ammonia i s c o n s t a n t * a n d t h a t t h e p r i m a r y a c t i n
p h o t o l y s i s p r o d u c e s h y d r o g e n a to m s .
No n i t r o g e n was
f o u n d a s a n en d p r o d u c t i n h i s e x p e r i m e n t s .
He g i v e s
t h e f o l l o w i n g m echanism t o a c c o u n t f o r h i s r e s u l t s .
1)
CH3 .CH2 .CHg.CH 2 .NH2
> UH3 .CH2 .CH2 .CH2 .NH + H
2)
H + CH3 . CH2 . CH2 . CHg .I'. U2-------- > CH3 . CF-2 . CH2 . CH2 .NH ■+■ H2
3)
2 CH3 .CH2 .CH2 .CH2 “NH------- > CH3 .CH2 .CH2 CH
N-CH^CHg.CHg.CH
a
-f nh3
He f i n d s t h e h y d ro g e n i s i n e x c e s s o f t h e ammonia so t h a t
n o t a l l t h e b u t y l a m i n o - r a d i c a l s r e a c t by ( 3 )
b u t some may
r e a c t as fo llo w s:
2 ch3 .c h 2 .c h 2 .c h 2 - i t h
>
CH3 .CH2 .CH2 .CH2 -NH2
+
C H 3 .C H g . CHg» CHg-Na
I n t h e c a s e o f t h e p y r o l y s i s o f t h e a m in e ^ th e r a t i o
o f h y d ro g e n t o n i t r o g e n i s a p p r o x i m a t e l y c o n s t a n t f a s fo u n d
in th e p h o t o l y s i s .
The f a c t t h a t no n i t r o g e n was f o u n d i n
e i t h e r c a s e i n d i c a t e s a s i m i l a r i t y b e tw e e n t h e two decom­
p o sitio n s .
T h is i s a c c o u n t e d f o r on t h e b a s i s o f t h e p r o ­
d u c t s o f r a d i c a l s , w h ic h a r e r e a s o n a b l y s t a b l e a t room tem ­
p e r a t u r e s , b u t n o t a t t h e h i g h t e m p e r a t u r e s e m ployed i n
th e rm a l d e c o m p o sitio n .
T h e re a p p e a r s t o be no e v i d e n c e f o r t h e R ic e m echan­
is m , a s t h i s w ould demand t h e e x i s t e n c e o f a n i t r o g e n h y ­
d r o g e n b o n d , w h ic h d o e s n o t a p p e a r t o e x i s t e v e n a t room
te m p e ra tu re s ,to
ju d g e fro m t h e p h o t o c h e m i c a l e x p e r i m e n t s .
S in c e t h e ammonia h y d ro g e n r a t i o f o u n d on p y r o l y s i s i s
-2 5 -
a l m o s t i d e n t i c a l w i t h t h a t in t h e p h o t o c h e m i c a l decompo­
s itio n ,
i f t h e p r e s e n c e o f t h e h y d ro g e n i s t o be a c c o u n t e d
f o r by t h e Bam ford m echanism , t h e ammonia m u st a l s o b e .
The d i f f e r e n c e o f t h e o t h e r p r o d u c t s i n t h e p y r o l y s i s , fro m
t h o s e in t h e p h o t o l y s i s , m ust be due t o an i n s t a b i l i t y o f
t h e com plex r a d i c a l s i n t h e h i g h t e m p e r a t u r e .
I t w ould be
a r e l a t i v e l y e a s y m a t t e r t o s p e c u l a t e on t h e s e d e c o m p o s i­
t i o n s , b u t in th e ab sen ce o f f u r t h e r e x p e rim e n ta l e v id e n c e
n o t h i n g i s t o be g a i n e d by so d o i n g .
Q u a l i t a t i v e l y t h e p r e s e n c e o f l a r g e a m ou nts o f
e t h y l e n e i s t o be e x p e c t e d s i n c e R ic e h a s shown t h a t t h e
m a jo r d i s s o c i a t i o n o f a p r o p y l r a d i c a l i s i n t o e t h y l e n e
a n d a m e th y l r a d i c a l .
The p r e s e n c e o f m e tliy l r a d i c a l s
w ould l e a d t o t h e f o r m a t i o n o f m e th a n e .
The p r e s e n c e o f c y a n i d e s m ig h t r e s u l t fro m t h e d e ­
c o m p o s itio n o f th e b u ty lim in o gro u p w ith c o n se q u e n t p ro ­
d u c tio n o f propane.
T h e re a p p e a r s t o be an a l t e r n a t i v e t o the f o r m a t i o n
o f a d e f i n i t e n i t r o g e n - h y d r o g e n b o n d , a s p i c t u r e d by R i c e ,
w h ic h n e v e r t h e l e s s n i g h t g i v e t h e same d e c o m p o s i t i o n p r o ­
d u c ts .
A t t h e h i g h t e m p e r a t u r e o f t h e dynam ic r u n s , t h e
e x c i t a t i o n o f t h e bond v i b r a t i o n s , p a r t i c u l a r i l y b e n d in g
v i b r a t i o n s w i t h f r e e r o t a t i o n c o u l d b r i n g t h e am ine g r o u p
in c lo s e p r o x im ity to th e h ydrogens o f th e m eth y l o r
m e th y le n e g r o u p s i n n - b u t y l a m i n e .
A s p l i t o f ammonia
m ig h t be r e l a t i v e l y e a s y an d be f o l l o w e d by a d e c o m p o s i t i o n
-2 b o f th e r e s id u e .
From an a c t u a l m odel o f n - b u t y l a m i n e
i t w ould a p p e a r t h a t t h e NHg was c l o s e s t t o t h e gamma
c a r b o n atom i f f r e e r o t a t i o n t a k e s p l a c e .
A s p l i t of
ammonia h e r e w ould l e a v e CH^.CH - CH2 -CH2 - , w h ic h w ould
be e x p e c t e d t o g i v e two m o le c u le o f e t h y l e n e a s i n t h e
R ic e s u g g e s t i o n .
I t d o e s n o t seem p o s s i b l e on t h i s v i e w ,
h o w ev er t o a c c o u n t f o r f r e e h y d ro g e n t h e r e a p p e a r s t h e r e ­
f o r e to be no e v id e n c e o f a d i r e c t m o l e c u l a r s p l i t .
-2 7
SUMMARY
(1 )
The p y r o l y s i s o f n - b u t y l a m i n e h a s b e en s t u d i e d
by s t a t i c m eth o d s o v e r a p r e s s u r e r a n g e fro m 3 , 5 cms t o
240 cms i n i t i a l p r e s s u r e , a t t e m p e r a t u r e s o f 5 0 5 ° , 5 1 0 ° ,
5 2 0 ° an d 530°C .
(2)
The dynam ic d e c o m p o s i t i o n h a s b e e n s t u d i e d a t
t e m p e r a t u r e s o f 6 5 0 ° , 75 0 ° a n d 9 5 0 °C . a t v a r i o u s r a t e s o f
flo w .
A c o m p le te a n a l y s i s o f t h e g a s e s fo rm ed on p y r o l y s i s ,
was made i n a l l c a s e s .
(3 )
The d a t a may be e x p l a i n e d b e s t by c o n s i d e r i n g
t h e i n i t i a l s p l i t t o be i n t o a b u t y la m in o r a d i c a l and a
h y d r o g e n a to m .
The h y d ro g e n a to m r e a c t i n g w i t h u n c h a n g e d
am ine t o p ro d u c e m o l e c u l a r h y d ro g e n an d a n o t h e r b u t y la m in o
ra d ic a l.
Two b u t y la m in o g r o u p s r e a c t t o fo rm a n im in e an d
s p l i t s o u t ammonia o r t h e y may r e g e n e r a t e t h e am ine an d
y i e l d a b u ty lim in o r a d i c a l .
The b u t y l i m i n o may r e a c t t o
g i v e p r o p a n e and h y d ro g e n c y a n id e o r p o l y m e r i z e .
(4 )
T h e re i s no e v i d e n c e w h ic h w ould s u p p o r t t h e
p o s t u l a t e by R ic e t h a t one m o le c u le o f n - b u t y l a m i n e w ould
decom pose t h e r m a l l y by m o l e c u l a r r e a r r a n g e m e n t i n t o two
m o l e c u l e s o f e t h y l e n e and one o f ammonia.
-2 8 -
r I B L I 0 GRAPHY
1.
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489, 1938.
2.
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199, 1939.
3.
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4.
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5.
J o lle y , J .C .S .
R endus, 179, 831, 1924.
1 9 5 7 , 1954 .
6.
E m eleus a n d J o l l e y
J.C .S .
9 2 9 , 193 5.
7.
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J .C .S .
1 6 1 2 , 1935
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C a r t e r , B a s a n q u e t , S i l c o c k s , f r a v e r s an d U i l s h i r e
J.C .S .
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T rav ers
495, 1939.
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13.
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14.
T a y lo r - J .P .C . 34, 2 7 b l, 1930.
15.
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lb .
S ch u m ach er an d U i i g
17.
Upson an d S a n d s .
18.
H urd a n d C a r n a h a n .
19.
B a te s and T a y lo r .
20.
T a y l o r an d Herman.
21.
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22.
T ay lo r.
23.
T a y l o r and A c h i l l e s . J . P . C . 3 5 , 2 6 5 8 , 1 9 3 1 .
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J.P .C .
3 6 , I9 6 0 , 1932.
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1360, 1939.
56, 214, 1934.
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J .A .C .S .
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4 4, 230b, 1922.
J.A .C .S . 52, 4151, 1930.
J.A .C .S . 4 9 , 2438, 1927.
J .P .C . 39, 803, 1935.
J .P .C . 3 9 , 1103, 1935.
3 6 , b70, 1932.
I
-2 9 -
25.
B am ford.
J . C . S . 1 7 , 1 939 .
26.
R am sperger.
J . A . C . S . 5 0 , 7 1 4 , 1928.
27.
R am sperger.
J .A .C .S . 49, 912, 1927.
28.
R am sperger.
J .A .C .S . 4 9 , 1495, 1927.
29.
B i l g e r and H i b b e r t . J . A . C . S . 5 8 , 8 2 3 , 1 9 3 6 .
50*
C o f f i n . Can. J . R e s e a r c h . 5 , 6 3 6 , 1 9 3 1 .
31.
R ic e and G e r s h i n o w i t z . J . C . P . 3 , 4 7 9 , 1 9 3 5 .
32.
Thompson a n d D a i n t o n . T r a n s . F a r a d a y
Soc. 33,
1546, 1937.
33.
P e r k i n s a n d Thompson. T r a n s . F a r a d a y
Soc. 32,
1466, 193b.
34.
R o l l e f s o n and B u r t o n . P h o t o c h e m i s t r y , P r e n t i c e H a l l , I n c .
19 3 9 , P . 2 1 7 .
35.
S te a c iC • J .C .P . 2 , 345, 1934.
36.
S t e a c i e . J .C .P . 3 , 344, 1935.
37.
H i r s c h l a f f and N o r r i s h . J . C . S . 1 5 8 0 ,
38.
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L ib ra ry
■N, Y. Umv.'
1936.
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