The effect of pressure on the reactivity of organic compounds

SOPHY

SITY

1961

CHEMISTRY

OEPT'i. LIBR. 'tHESIS --'---·~

1

A D D 1 ) 3)

4)

5) 1) 2) 3) 1) 2)

c

s.

..

s Contribut

• • • • • • 4 • • • ~ •

" "

..

..

ssure

.

..

..

..

..

_{" "}

..

..

"

"

..

"

• "

A

0 R

D 1) 2) 3)

4)

5) 6) 1 ) 2) 3) l+) 5) 1) 2) 3)

4)

5) 6)

7}

8) 9) 1) R LlG AV R a) b) c) d)

..

..

..

..

_{" "}

..

.. ..

..

..

..

..

..

"

D.V Hammett.,o;

"

.

.

~

.

.

.

.

. .

.

. .

. .

..

II

"

..

" "

..

..

..

..

"

..

..

_"

.. ..

..

..

..

..

_"

Rate C

a.

..

• • • •

•

• • _"

..

..

..

o ..

..

.

..

2) a

"

..

..

"

..

..

"

..

..

118

a) J:::,.V• _{values ..}

..

_..

..

_..

..

_•

_..

_{.. ..}

_..

..

_{• 118}

b) A

.

_-·

..

..

_•

..

_•

..

..

" '"

..

..

1

e) _"'

..

_{" ...}

..

..

..

..

..

0

..

" ,. 1

c

_"

_..

1/.

..

" "

..

..

..

" "

..

1

e)

..

.. ..

..

over a 1

benzene

UNIVERSITY OF

I

on

'

.

'

measure can

cases.,

by

resolmnce a

a

resona:ace

;o·

6' (1)

(1) can

(

(2)

of'~'P~

%?[- (

Ll.~G

= (•.DAV*")/2, T 6

;6 L\

v;

tJ

b.V;

is

4

,.T .. 6 )}

(4)

a var

on

a

e

heirolytic

ase 1) ..

e

Fo~ a

more

a

case

f

Oases 2

5

5

e::.v*

b

s to

an

Case 3,

--~

S-.Rol~

_{- C-X + Y - ----7}

Ro ..

_-c

_H

~

_~ -', 2.

- H - ',

~-2

13 on

1

:non-11

rr EUl1TntUll1 and

v,rere

is some

1

)

13

PRESSURE

PIPE

FIG

II

I

THRUST

4 1

-SCREW

BOMB

---»--HEAD

B

I

~--~---·--- y ---:>: A

L---l: _____ -- .

.vx

··---I\

BOMB

CAY IT Y

, A

[image:21.597.75.559.68.744.2]

Nt c fiR nn1..: IN/Ri!

o·o22" cro:t.

ST¢<c-l. 61/U<uv'Cf.

[image:24.597.40.555.58.775.2]

.5 Ct'{~ 1..1

FIGI12

FIG

.:SIL..V'<IC~ sr~:.c~ WFtsut::llf;

3

FIG

ll

4

SMALL ORIFICE

814 SOCKET----+

CELL

PLATINUM ELECTRODES

NICHROME WIRE

~----TEFLON BAG

c

VARIABLE CONDENSER

FIG

II

5

OSCILLATOR

A

B

CONDUCTIVITY CELL.

[image:26.597.38.557.63.745.2]

1

11,111 .. 1 1

1

as area a,.

K/c ( 2)

ons )

)

"

'(

K v2 0 _{0 + . 1}

-

(4)

1

(5)

(7)

'A'

can

t f

1

an t

..

A on

cone

'A

1

:f'

'A'

'A'

" ot; ::;:: 11-"A'

I

'

I

2 8

1~

1 ~3 ::;::

1-~3

t:t

( )

:1,/~,

)1 500 1000 1500

1 t~ 1. 1.1 1c~1 1.1 1.

001 1 1 .. ·t.101 1.1 1.171 1.1 1 ..

o.

1 1.054 1. 1 .. 1 ·J,.1 1 . .1 1, ₇

1 1. 1 .. 1.1 1·1 1 • .1 1. 7

o.

1 1;. 1 .. 1 .. 1 1..1 1 .. 1 1. 6

mean 1 1 .. 1 .. 1.1 1.1 1 1 .. ₇

Ao

:0::: 16

)1 1 2500

0.,001 1 1.037 1. 1,. 1. 1. 1.

0.0015 1 1 .. 1 _1·078 1. 1. 1 ..

1 1 .. 037 1. 1 .. 1, 1. 1

rae an 1 1. 1• 1. 1.~

1 1

none (115 .. 0) 1. 1. 1 .. 1 ..

i .. 2) 1 1 .. 1., 1 ₃ 1 ..

(1 2) 1. 1 .. 1 .. 1.,01}.8 1 .. 040

(1 1 .. 041 1 .. 1 .. 01+9 1 ..

044

1 ..

(11 4) 1 .. 1 .. 1. 1., _1" 1 ..

(1 9) _1" 1 .. 1 .. 1 .. 1 .. 1 ..

( 108 .. 4) 1 .. 1 .. 01;.1 1 .. 1" 050 1 .. 1 ..

)

'Ao

1 1

none ( 107 .. t}) 1 .. 1 1 ..

(1 _"7) 1 1" Oit.7 1 ...

(1 ) 1.,01~1 1 .. _{1 "}

(1 7) 1,. 1., 1 ..

(1

4)

1 .. 1 .. 1 ..

(1 ) 'i .. 1. _1"

(1 2) 1 .. 1 .. 054 1 ..

(1 9) 1 .. Olt.2 1 .. 1 ..

p ) 1 1

1

n

u

)

1

1 1

1 1

1

1 1

11 14

1

1

1

3

!t.35 .. 10

1

1 1

7 ...

"' 2

'i 1" 3'1

1 1 1

6 ·:r '")'">'Cl

~ '- u

30

e

) /1 "A'

¥;

1 1

II 1

II 1 1

1 1

" 1

" 1

1

1 tl-1 048 152

" 1

, 1 1

II 1 1

1

1

1

1

"

II 1 1 971

" 1 1

77

1

1 ₇₄₇

" '1

1

1 1

1 1 ₁

1

1 1

II 1

1

u n u H

"

n II ,, 1/ ,, PlbM,) 1 1 1 1 1000 1 3000 1 1 i 1 1

/1

I

t;

1

9571 9.

1 63

o ..

414

431"' 10

9571 870

1

)

:::1'

)(:

1

₁₄

H

1.

1 1.

H _{1 1}

1 .. 1 It

1 .. 1

H ₁

tJ.19 6

11' 1

It

1

H ₁

1

n _·1

tt ₁

1

1 .. 1

It

II ₁

1 ..

1 1 ..

1 ..

n ₁

1 ..

)

_:A

I 2

p

3":t

0 ..

974

4 ..

₇

n

415

u _{1 l,j..,}

tf _{1 1}

It

1

It ₁

021

1 78

o.

0

76._

₄₁₄

tt

₁

₂₄

_{419 ..}

780 4 ..

H _{1500 30}

774

u _{1 40}

H ₁

l.J ...

'11 _{1 970}

9 ..

4 ..

01

1 .. 1 61 .. 04L} L~ .. 516

u

970 4,.416

it ₁₀₀₀

11

tf

1

n ₂₀₀₀

n H 8 974 !! 974

tt _·t

4 ..

313

H

1 1

H ₁

1

9

.,

II

,.

f l

.,

P ( 6a.v-s) 1

1

1 1

)

1

1

1 13

1

411

4 ..

74

4

9714 410

9710 14- ..

0

4.

o ..

4 .. 1

1

4 ..

013

c

A I

t~

4.

1

_4,.

₉

. u ₁

_{7 ..}

u

n _1.

1

VI ₁

₄₁

_!~LJ.

It

ff _{101 ..}

000 1

..

u ₁₀₀₀

_{77 .. 09}

_L~1

n

n

₇₆₀

400 1

0,..9604

Lh314

1!' ₁

n ₂₀₀₀

47

n

111 1 51 ..

1 71.

"

"

It

1 .. 1

't-.r:~

1 .. 1 83 .. 379 .. 0 .. 9545 1 .. 158

936

It _{1 11}

₄₁

o ..

1 .. 794 3 .. 746

tt _{2000 1 30}

o ..

It _{3000 1 460 .. 67}

o ..

577 446

1, . 1 8!+. 379 .. 47 0.9549 1 .. 131

n _{1000 111 .. 415 ..}

_{o ..}

1 .. 749 757

H _{2000 1 70}

o ..

_2.

II _{3000 1}

53 9538

1 .. 1 80.14 379 .. 1+7

o.

95lt9 1 .. 058

"

1000 1 l~1

o ..

n _{2000 1 .. 70 l,iJ-42 ..}

o.

II _{3000 1 ~ !~1}

Oono.

3 P ) :;}

0-'2-

o4

0 -;;I j;

2.184 1 55.-34

..

0., 0,.6610 4.1

n _{1000 75.31 418.}

_o.

_{1. 1}

3 .. 974

n _{57 445 ..}

_o.

_{1 .. 580 801}

u ₃

1 .. 1 4 .. 184

If _{1000 1 41 1 .. 056}

976

n _{2000 1 1-+46 .. 00}

_o.

_{3 .. 802}

n _{3000 154 ..}

_{o ..}

110 1 _0.9594

It ₁₀₀₀

o ..

n _{2000 1 0.9571 1 .. 590}

n _{3000 1 46lh 24}

_o.

₆₅₁

1 .. 1 70 .. 0.;. 0 .. 6730 Lt ... 172

if ₁₀₀₀

l+ 1 30

o ..

1 .. 080 3e

If ₁

1 "

If _{3000 1 JJ,l~ ... 49}

641~

2 1 9571

u _{1000 81 .. 0,. 1.,080}

u ₁

_o.

_{1 .. 601 3 .. 796}

H _{3000 1}

o ..

_{2 .. 279}

1 1 43 .. 3!~ 91 0.4410

,, _{1 67 417.,80}

_o.

7164

" 41+4 .. L~9 1 ..

p _{) ;j'}

r;

1 1

1

ll

1

3000 1 :2 8

1 ·1.,,

o.

_l~39L~

II

1 93 1+17 ..

o ..

7170 4 .. 14L~

!I ₂₀₀₀

n _{3000 1 0}

1 .. 1

1

2000 f37 ₃

n _{3000 11 62 B10}

8 1

" 1-tl.t-01 lt..

·t 1_{J•17 °5}

~-.. , ""' :/ 0 .. 71

2000 444.,74 1 .. 074

1 1 2

1. 0 1 377.57 0., 0 .. '7750 t\. .. 11"1

n _{1 L~14 ... 1:) 3 .. 0}

II _{2000 1 L!l+O .. 62}

01!1 1

tl _{3000 1}

.. 28

1 .. 1

!I _{1 4Ht .. 13}

1 _{3 .. 7'19}

)

_-;;'

'6

-1:.)..

1 .. 1 51

o.

lt-..112

1000 41L~ .. 15

o,

1 05 L~.0 .. 58 1 .. 816

n ₁

"18

1. 1 1 Ol.t.

H _{1 l~.l.j.O., 51}

1 .. 1

1 .. 1

H _{·t 1}

11

1

1

..

1 .. 1 7405 lh 1

1 _{1" 180}

1 .. 1

!! ₁

97 .. 93

41

1 ~ 154.

1

41

1., 713

II ₁

6Ht.

1

o ..

It ₁

1 .. 19•1

1 ..

p ₎

_?'

'6;

o4

1,. 1 _•

o.

h .. 1

1 94. 419 .. 1 .. 191 9

!t _{11 .. !~3}

0 .. 9571 1,.

II

141+-15

..

o •

3 509

1 ₇₄₅₄ Lj ... 1

"

1000 419 .. 1 .. 1

H ₂₀₀₀

11

o.

95 1+46 .. 1 .. 7B7 948 It

1

c e) -;j

41

'l:l::l... o4

1 .. 4 1 87

o.

6

o ..

4.219

!t ₁

₇₇

_lt20,

o ..

₀₀₉

tf _{115.,L~O 1 8}

n _{1 095}

litt ion, Por

f::Hli' e , as

solut

of an unc

s

OI~

was

a litt

20

_..

measurements e, ar•e in

a

some-..

7

2 2 ₃

425

1 1

3 2 1 1

2 1 1

4 ..

110 1

on one t

i .. e ..

t

8

( )

_r

r s

_s;o

(

1 1 .. 039 :1 013 014

₇

3 1. 013 014

1 1 .. ₃ 1+

1 1 .. 3 014

1. 013 i~

4 5 0

8 ( )

b)

s) _[->

s;

n

..

1 8

1 9

0 9

1+17 010 ₉

esonance

0

p ₁

0 1

( )

6.V ..

5

9 ion

6V ₌

II' or 6V₁

the same T

11 .. 09 9 ..

H

1

1000

can

(See

s

ion 5)

6V 1,

one

'

a/oP

(ln K)

by

2 1 47 8.84

1 1

11.77 1 16 11.

2500 3 0 .. 558

terms

the

s ar•e

2 ₃

56 1

reasonance

6V

(

ze:rw

D. b. V is

e ..

(by on

1,esonanee

a b.V versus <Y"

not

i :more

resonance-s comruon are

, in

a

more

resonance

1 on D.V/cr

more

or

one., over all,

it i of'

one

t its resonance d ( 1. e. O""R ) is

i ·· 1-+-+--1--1-+1-~ I +-+-t-t-1'-.+-+4- e-~ 1-1 ift++1t+++1t+++ -1-1+++

1 +-4H-++--·t++-1-l-+---l--.;..-f~+-l-++-t-t---l

~I -'··

i--1-=r

i--- f-· f- --H-t--+-~-l----if-l--+-1--H++~-+-H--H-t-+-1-1-+-++c...f-++-t--t-++-•-t-Hi--+-f---.J.. ---I· 1- +-·1-1-f-·+-+~HI-+-+- -l-H-+ +-++-+-+-++++-l~l--1-l-+--1-+-+-+-t-1'-·l++-1-l-+-++~f.-ji-++-l--H-+ - --'-+--: · 1- --I i- --· r- H++t+t+1 - · -'-· '- -+t+-t-1-t-+-+·+--1-+-t++-1-+-+--1-+~-1-+-++-1--t-H-+-+-..; '--,-·--l !-- 1 -- 1-· -f-+++--t-t-+++-1-+-+++l-++++--l-+-+-H-+-t+-H+I-+-+-t-+-1-++-t++-++!-+++--hH---1 f-- I - r- '-ri-+-H+-!-1--+-±+-1'-+·H-f--H-++-1-1-i---~

1 -J--f.-ji

i.L ,_ -~ 5." _ -+-t-+++-'<::>-+1-+· _ -r-c cb i :_ i ---1---1--+-o~+ -f~ 1

t+-t-t-+H+1+t+-H--tlnt-+-+-t++-++-11-+-+++i-1 4-++.c-H

·-It is to on 3,

that, as P

s) 1 1000

-~v 11 .. 9 ..

'

6floP

₌

6~V/2,.

as 6. 6 V o~I6P

A[:j_ V zero seen

s

c

10

1500 2000

9 .. 12

a

s an

t

H

co

KNH₆

Ct

KNHl.

NHO

I#

>

H _{N H3.}

>

10

H

(A)

It 1 ar sm

s

X X y y

0

₊ y- k, )

(

k., k. )

0

+

x-

-ca.)

(B)

( )

ca.ses,

s, 1

resonance

a are

resonance

resonance

was

(C)

on

( 1)

,

near en~

llV*

sum

(2)

1

s ..

Bome

resonance

OS courset

a

FIG

ill

I

- - - - ·-

- -

-

-

- - -

-

-

-

- - - _. - -

-

-

-Br

Br

Br

A

CN

I

n

. - - -

- - - -

~---

-Br

Br

Br

OocH,

N02.

N

y

Br

Br

Br

Br

N02. N02.

Yli

X

- - - : - - -

---:---Br

Br

Br

0

_CHO

XI

~-~ - - ~ - -- - -

-

- - - -

-

-

-

-

-

- -

-

- - - -

-

- - -

-

- -

-

- -

-

-

-Br

Br

[image:83.597.26.582.73.803.2]

s

A

D,

..

s of

corres-the reactivities a es

course it was

L

1

1

was

b)

new

s

YH!' 1

c) R O::rl a

a:t•e D 1

d)

)

s

8-was 1•un

just

was

T were

a

..

g)

s can

c

..

,.H., was

1

M P .. 1 ( 127°) ..

-

A commerc

P., 112 .. 5

-

11

)

..

was

"

vacuum-"

e to remove

was

0

77 ..

)

to a

=

1,.84;

).

)

)

..

5

-vacuum

5

CH3 CH~ CH?.

Nqo~

NOz. NqoNO.,_ N01.

0

N07.

>

lh-

-~)

I~

--7>

I~

(i)

'

0 ( ₀₎ :1!

( )

N07. NH7. Br

!I .. 1

ac

7.,5

- 171°

( ) was

(

)

( 5 ( 1 .. 5

(5

(iii) 2,

some

( ) was

4.

were

15 5

corres-H Ac

\ /

N NHAc

N Hi.

~

H, _ _

HA_c_~>

ll_)

Ac2.0

6

CH_3 - - - - ? >

/./ Br-2.

>

OCH~

HCI

)

0c

H3 _ _ H_N_0-"'2.=---;i!>)

y

CuCN

Br

(i)

( 17

CN

A C H 3

y

Br

Br

) waa

{

)

(7370) was

(iv)

)

"

NH?.

ooc~

Br

( 1) ion

HN02.

>

Cu.CN

CN

AocH~

v

_Br

( )

H

( )

t"'tS raue if:i.ltrate

c

H 0 N

r:1

}o .52 2-.54 20 ..

64

44

3

..

6 01+

(

one

to

(i)

with

( 10 was

excess

sol , dilute

e solution, er•

alcohol, which the pure (

as (15

(ii) 4-Ethyl-3,

5-(44 a 1

to a

, to remove excess

A

( )

(

)

""""~M..!J<;; ... ,,.,...,. by

" ' " '1''\T>I<>T> \,;>1Uf.UnJ.J.._,iA was UU<!<LU •. >z:> on

)

65 12

lt 5

96

19

excess

15

( 80';()

1

(

two

0

1 1

at

X 1

6

-4

a 5 ..

1°/760

rmn .. , was

use ..

to allow the

R

enes

s

t

to

a

non-, on

use

Here R is

t

on

=

1 ) .. 1 x1

(3)

..

s were

FIG

III

2

[image:105.602.49.562.56.772.2]

:non-

t

(1M .. ) that

were carr

( cone

91

ot:

p I( ( ) R (

)

1 5 11

1 1016

1

1

1 11

, _L -1--+-+ 1-+-+-f.++ .1 ~

i-

L' . .j __ j_

~-+j --i-- -!.' -L-l-1--J -+-.J-.+--1-+++++-+-I+H-i--t-t-t!--lll_l _ -r--f-- t-1 +-·t-1-,+-+- -+ 1- --1-

-1.-L ~+--1--1~++1-1-+--t+-t-:---H- -!-- - i--l-1--L-H-l--:l--+++-+--+--H t- .!---+---+--'•-+-+-+~+- - t - t--

+-r=t=i-

f-- :- __ r- 1-· ···

--+~---1---·H--+-1-+-+-++t++i++---+t-_t,..++---H+r·r-t-lH-t'

-r-r-t-Hitt:t+f--1--- -r-r-t-Hitt:t+f--1--- -I---+~i----f--+-1-+--t-+-t--t-j

,__,

I

-1

)

~·-

h-t--j:I+

!-'- --_I

b-+-ieltL +

ease

)

)

p _{) 1 1}

/11'1/J, 1 1 "171

/Jp/4, 1

no

1500

1.

1 ..

A 0

2000

1 .. 1

1 .• 1

c

3000

1~

1 ..

(I ,. ).

were to

A

c

(

was so

c

7.. 1

1 04

..

(

d

0

"'

..

46 ..

)

II

6 ..

6 ..

or

)

a

manner

N

11 .. 11 ..

1

excess

(2 ) was

'

(

.. P,.

N 11.

'

ethanol to (1 50%) ..

:-(concentrations dissolving the accurately

was filled

piston could

was filtered

for

c

₁

)-benzophenone)

1

into the barrel, thus fine e was then

r

c

81 ..

48

81 .. 47

... 10-2

::> X

(

excess reaction

'

n

7 .. 00 7 ..

and the two cell were

the whole operation could

any

to

the bomb

insulation

initial

one hour was init

in a

The cell 1

bomb.. After the hydraulic

hours were

N

5.

5 .. 28

up by

1

10, 000 ohrns. some

so that one

the

time ..

(10,000- 500 ohms) within a

(on

reed

was

the

in

as zero ..

e

c~:.u3e.

for the

(t~) P .. t7)

the All

the

product, at

mean

for the

1

er needle, througll a • .,.,..,.,.-~-·"""'''"•

ance even

Vias still a

rate

was stax•ted

minimum this

)

of one sec

500

was d( 1;1t )/dt

of'

ion

could

in

dx/d( 1/R) was by

the plot ( 1/R)

mean ( 1/R)

were

tion

Run II Or

Oono ..

Cone ..

was still

The above was compound had reacted.

III

Cone ..

ax/d(1/R)

=

1 ..

d(1/R )/dt =

o:f'

over the

=

o.

k:::: 2 ..

1

the

the o:f' rneasu1•ernent is

when 20% the original

bromo-=

1.,067 X 1

=

o.

k

=

/mole/min ..

of

(a T (

c

1 0 R A

=

k =:

I)

1;Rx1o3

1 ..

1 .. .5106

1 .. 5152

1 .. 1 .. 1 ..

( 1/R)

) ove:r• t

)

d:x:/d( 1;1,{)

1 .. 1919 X 1

t

R 650

t is

d( 1/R )/dt

=

~

..

$ are

1/Rx1 1. 1 .. 1 .. 104 "

1 .. 5480

1 ..

105

In ( (4))

the dx/d(1/R).,

, the

may error

as were mea "~ ... ~1'1-,

eould

d(1/R )/dt in

0., R

2 are

.. Only k

k are

)

1 63

6.99

1000 10 .. 10 .. 54

1500 15 .. 15 -1 ₀₁

2000 20.60

_•

30 .. 21

3000 L~O .. 41 .. 20

p ₎

1

3.

61

4-

19

1000 7 .. 24 7 .. 20

1 1 80

1

3000

106

~onstants, k, (in

_I

:for

piperidine in

are given,

the

were 300 k

3.74

6 .. 43 6 .. 63

10 .. 43 10 ..

14 .. 1 02

21 .. 62

..

81 _•

40 ..

40 ..

54

4 .. 84

4.99

7.12 7 .. 19

10 .. 40 1

1 !~0 1

15 20 ..

15

P(bars)

1 08 04 2.10 2..-07

500 2.45

2.51

54 2,.50

1000

3.

31

1500

4 ..

18 4 .. 18

4 ..

18 l+-18

2000 5 .. 61 61 6.3

5.

2500 7-05

14

7 .. Hi 7 .. 12

3000 8., ₇₅ 8,.70

P(bars) Mean

1 1. 00 1 .. 99

500 1;{.. ₈₇

4 ..

₉₇

1000

80

6 .. 62

i 11. 11 .. 11.,l:t.-O 11 .. 3!~

1 16.,03 1 14,6 16 ..

2500 12

01

4.8

30 ..

47

l?(ba:r-s)

1 0.,76

o ..

0.,73 0 ..

71

o.

1 .. 1. 1 .. 31 1 ..

1000 10 16

14

1500

5.18 5. 21 21

7 .. 7 .. 46

108

P(bare)

1 1.24

1.24

1.- 1.

500 2.1~2 !~2 2 .. 44 2~Lt-3

1000 L~ .. 18 4.20

4 ..

18 l,~. 19

1500

7.

6.81

6.76

6 ..

10.09 10 .. 11 10.,15 1 12

2500 1 71 1 78 13. 1 72

3000 1 19 .. 52 19.

P(bars) Mean

1 00 1.89 04 2.18 2 .. 02

500 6.18

6.

6.19

6 ..

1000 19 .. 64 19.58 19.38 19.

1500

30

52 .. 48

50 ..

77

53. 51 ..

2000 109 102 102 104

P(bars)

1

{1.56

1 .. 70 1 ..

37

1 .. 57 1 .. 44 1.61 1 .. 54

500

1000

_3.69

_{3 ..}

1500 4.86 09

2000

_7-79

8.15 7 .. 97

7 .. 97

2500

15.97

16. 16 ..

91

16 .. 40

1

P(bars)

1

i

_o.

₅₃₇

0.578

0,.612

_0.573

0.581

0 .. 557

500 1 ~o; 1 .. 1,. 08 1,.08 1.06

1000 ₇₄ 1 .. 74

17

1 ..

87

1 .. 88

1500

~

45

61 ₈₄ 90 .3.-09

4lt.

54 3 .. 84

2000

{4.47

_{4 .. 33} 4.90 _4-49

1.4; •• 62 lh 1.3

2.500

;.

; .. 87

3000

_7-51

7.64

7 .. 44 ( .. 53

P(bars)

1 21 2.70 42

94

3 .. 07

500

4 ..

58 ! .... 75 4 .. 74

4.69

1000 6,.86

6 ..

6,.90 6.90

1500 _9-73 10 .. 03

_{9 ..}

g ..

2000 13.64

13.

1 13 .. 45

2500 18 .. 81 1 30 1 55

3000 22 .. 82 ₄₇

_{24 ..}

₀₃

)

p

1

4 ..

4 ..

17

21

_4.

500

7.46

_{7 ..}

7.48

1000 1

60

10., 1 10 ..

1 {1

~13

..

1 1 1

2000 19 .. 1

18 ..

30 .. 29 ..

.go

110

~--~~~~~~~~~~~~~~~~~ - The results at

a trno SJ>her ic

011

s,.

Br

0 0

CN N~

I IV

<9

0.374

19.9

The most

dinitrobenzene (VII).,

approximately the sarne

constants, it

stud1.ecl

ivit at

Br

Br Br

0

NO,_ NO;t

0 0

COCH₃

COC<..Hs-VII XII

20.,2

_0.307

0.,423

(

)

are highly activa.t

:F'rom the

1

both substituent dinitro

ive of the because, on

"additivity constantan , :2:..

o-the

IV or VII, but is more

(XII)

ive than

This is

is

case, as

c--a

for

on

and so

In connect with

noting that the uncertainty

the common

{XI) ..

cr-

for

the

in

'

ing methyl the

Thus

·than

less

I ..

,

is worth

about an extension of the

ic Stlbsti tution

effect, which is portion comes into play only at

112

3 all the ier

to findings at

occasionally to in

x•esults v1hieh pressure, and

s of the

3

Oompotmd nne leo- solvent Temp. . R

(1./mole/sec.) ence

J!-Brorno- piper benzene

_{99° 64 .. 5x1o-7}

54

nitrobenzene dine

D-Bromo-

_"

n n

_1.98x1o-

7

u

benzoni tr ile

acetophenone H u II

o ..

_{86x1o·7 n}

J2-Dhloro ... H It _100°

16 .. 8x10-7

_·J05

nitrobenzene

J-Dhloro .... 2- !l u n

6x1o-7

H

nitrotoluene

5...Chloro-2- If H 1t

_{14. 3x1o-7}

fl

nitroanisole

0.-Chloro- tl H It

779x1o-7

It

nitrobenzene

u H If

772xio-7

H

nitro toluene

3-Chloro-1. .. - II t1 _2630x1o·7 tl

nitroanisole

]2-Fluoro- J.j.9 ..

5'

2 ..

37x1

102

nitrobenzene

3,

initro- u u It

-3

th 19x1

o

H

fluorobenzene

§-Bromonitrobenzene

(hrs.-1

1

reflux 1590x10- ·

₅₇

.3-Br•omo-4-ni trotoluene ( 106°) n

1400x1o·.3

H

4-l1romo ... 3-nitrotoluene tl It H n

n u u

_o.

_7x1

c:r

3 H

u u n _0,.2x1o-3 H

u n n _79x1o-3 n

Br-0

eN

I

3.74

at

of this

Br

OcH~

CN

II

5!~

for the

20.68 It may be seen that the methyl group

(in II) has little effect on the I what 11 ttle :it

features are the ones; the m-rn"'T. an

electronic electron-donor by comparison with

ef'fect small.. This accord with

the assumption that any steric of the cyano group is insignificant ..

supports methyl group on

sterie

effect

should absent in III. Now III reacts than I

II and a reason must in el .,. ... ,,. ... s.. There are two possible

group ( ~ +T) is an electron-wi thdraweJ? and

be that the cross-conjugation illustrated below would activat the eyano group and therefore act as a rat factor.

)

Br

~~a·

y

.,.'cH

rr

~

-Clearly ia

results

the

105

on to support

present finclings. a of' ohloronitrobellzenes

ituents in their 't"eactions with

in 100°. Relevant are

Table 3 , 3-Chloro ...

4-nitro-toluene. and 3-0hloro-4-nitFoanisole. this of

aetivat nitl?o reaction

site the situation more

tuted conrpounds. However, a st

the

effect, reaction dealt with is

steric

f'iable to

obtained

of the reac·&ion site may

to

ectronic effects, s

compoun.ds are clearly in line with those :found in The

as

and s

57

is agreement wtth the

seen

~-~~~--- ... this series, unlike A, st

interaction bet'Vveen substituents should. be

Comparison be made within B IV

, and be drawn between the

B the of A~ is series

:f'rom steric

6CH3

NOl.

v

0.730

Br-0

OCH~

N02.

[image:137.595.64.521.601.783.2]

115

one,

on site, bttt t't'<o<>c'nA

the activat inhibition

of mesome:t"ism.,. It is gene:r•ally

t'lll:'n a nit:ro group about its ring-nitrogen

torce methyl g:x·oup out of the plane of

(

the ring-carbon bond. It may

111. e than tllat this is a result

ions, some

A

on is

( above) ot'

nitro (

On present results

relative

importance of

di

are

to than it is to

by

seen

to

account

noted the

VII

02

are:-102 _{studied the}

VIII 0.,1 methanol 116

A

No¥Noa.

C~Hs

IX

0 .. 573

ic results with this compound with that the compound. is rather

work little difference

I was ob two sets results are

ivity

group

the fluoride ion with a metho:xide ion

aou.lrl

reactivity smaller by a

groups may the

but they are <"''T>I!'>nn, the resonance

is

but,

of 13

a

two however, may factor 117

,

ivating a a combination of

effects is much more

'fhus, (see Table 3)

is five times as

likely

to

vity

of than VIII .. is

one also,. Both

in ion of' the

ive in

~~[k~""j'"" Ping

In add it. ion

that of the hypera:onjugat its

on reaction site~ is

it that is to

deaetivat

convenient to

inductive

than a ,m-methyl _"

a k

the an

discussed are

in :I>eaeti ...

(IJ()

this

a

rate group should

ethyl

and this should

reactive

IX as eompax•ed with VIII ..

effect the ethyl , both on the nitro

than that of in in

and in

it is mo:l'e

, is that

a at

and

in stabilizat

polar

this factor is of no

the

more

aol vat ion. in between

en" than between VIII

eonelusion as to importance

effect, above, at

2

T

formation of act

the

vary fol'

Compound

.,.. LlV 1

- e:;v:li!

=

2 • .303 RT d/d.P(1og k),

8 ce/mole

VII ..

I

31.8 21.8 1 8 42.1

is no

III

VI VII

2

37.9 69.1

by

116

bigger

groups

VII should

is and

hold.

*

seen that D. _{V 1}

the

), obtained

-69 .. 1

XI

119

ivity

that in a in

an substituent

( ~ positive), an

contraction of

that the tuent, the

1.6

v*

1.

s

7

by

was

that quinolines

even more so in the

s

electr

O H .•. H.L.J...U. be

*

in b.V

to

:polar• react

the

dissociation the introduction

, to charge

(Hrunmond' a

entirely due to a the transition

postulate, P., t:>s) ..

may

one

a major one ; it

ion substituent

in ivated cornplex..

1 mainly, by

..

this Thus

to the conclusion of' subst

be illustratecl

,

k, the ion

1:~ it

at

120

with the t•apreading

ot

charge effeot11 _..

•

The values 6 V are

rate constant with

of simplicity, in

from the

{see equat

e of change

). For variation

discussion, the

•

rate constant with pressure than 6.V values with the factors in mind, of the

(A, B, 0 and D) is in turn; mean k values and

k_p/k1

'l'ables

at the various pressures are collected the

and kp/k1 are plott in 8 - 11 ..

TABLE .5

Br Br Br

0

QH3

OocH~

CN CN CN

I II I I I

P(bars) kx.1

o

6 ~/k1 1tx10

6

_kp/k1 kx10

6

_1),/k1

1 3 .. 7Lt- 1 _{3 .. 54} 1 20 .. 68 1

500

6 .. 63

1 .. 77 1-t-.. 99 1 .. 41 24 .. 99 1 .. 21

1000 10.,62 2 ..

84

7 .. 19 2 .. 03 33.12 1.60

1500 15 .. 02 4 .. 01 10 .. 63

,;.oo

41 .. 80 2,.02

2000 21.29 .5.69

15 .. 53

4.38 56 .. 19 2.72

2500 29.85 7 .. 97 20 .. 15

5.69

71.15

3 .. 44

3000 40,.62 10,.85 25.70

7 ..

26

86 .. 98

4.21

(I) 5·bromo-2-oyanotoluene (II)

atmospheric pJL'essuJ?e., Therefore, from the above discussion , the variation with pressure of e constants should comparable.. From Table 5

[image:144.595.71.550.135.632.2]

some

reaction

rate constant~ varying the solvent in

the

group,. Solvat

the polarity the solvent is

at a given vary

1

the

tle steric the

increases,

:in the in test

earr out ..

lti/k1 values, manner.

III Table

5,

and ing that the from that for I, it

in direction the

b

with

involves

; the

scussed on P .. ti'J ..

essure

I<;_p/k

_{1 ,} the too small to be

factors that inhibit o-:f' second

cross-conju.gat B atrnospherie .,.,..-,r..,.,.,,..,ivelf

to

to be er

the results

on these

it resonan.ee ..

ion as d.i of'

It 'Nas noted.,

for eyano , that the methoxy

methyl this

to oscillating about a m.ean position, an

would its amplitude

ot

oscillation the incidence of

configuration. This

aoti vating ... .,.~'~~'""'..,.. _{the cya.no group}

the reaction \Vith

possible explanat

to compound I.. This; then

A cho iee betvreen the two

bilities is difficult to

somewhat more contrived.

~--~~~~

-

6

below

tor this

the compounds are plotted

TABLE 6 Br

the second one

the relevant data

and the ~/k

1

values for Fig. 9 ..

Br

Br

122

in

0

0

CH₃

0

OCH3.

NO~

:rv

P(ba.rs)

kx1d+

_~/k1

kx1o4

1

1.99

1 730

;oo

97

00 1.33

1000

6.

2.14

1500 11 .. 70

2000 1 34 21 20

2500 31 11 .. 21

₅₃

47 15.31 10 .. 79

It can

( is "'""""""'

(Table 5).. From

a.t ions (P. 119) the of

NOa NO;t

v

I

kpk1

kx104 _kp/k1

1 1. 1

1.83 1 .. 94

ih19 3 ..

5.;.01

6.

50

7.12 1 12 8 .. 11

10 .. 1

72

11 .. 00

1lt .. 78 1

57

15 .. 69

that k at one bar than that for

constant with

[image:147.595.69.524.113.750.2]

variation

must be

Sol vat because of

is

group·

area over

which

tor

IV

charge

1

tor

r ..

nitro

( oxygen in nitro

o;vano~ The solvation

greater this ease.

as compared

of

one nitrogen in

V1ould therefore be

a second be

ity considered.

by the increasing to

become more benzene in a to

that above the methoxy gl'oup.

withdrawing ability the nitro g':roup would.

as pressure is increased.

s

impossible

the eyano group, it account~

comparatively

tor IV th~tn for I.

rate se with

Turning now to compounds V and it is of

, for

to

compare F 9 with 8.. It can seen that variat

with l' of the constants of all compoun<ls

series B are almost rate constants at spheric

vary significantly , while relative

vary a littl are compared

f'ouncl for that

the

faetora 'W ...

B and in series must be vv:r""'"'·"" for .... s f'aetor

mu.st not only explain rate , wrtieh

greater for V provide an explanation

for similar VI

important

between

124

the methyl ~~oup in V or the methoxy group in VI.

The rate constants at atmospheric pressure that the

ni tl"O group in V is forced out of the plane of the benzene

ring (see ea:t>l cliscussion).. !f' the effect of pressure is

progressively to force the nitro group back into the plane of'

the benzene ring\!' the aeeeler•at ef'fect on the rate of V as

compared with II and V as compared with IV may accounted

When VI is it will be reme.mbered that it has

been previously that the met.hoxy group is effectively

bigger than the methyl group~ and therefore the nitro

grou11 out of plane more than does the methyl group. If' this is

so, then the u:rlatteningu effect of pressure liltely to be more effective with VI tha11. with V and the urate increase"

sequence of' B is tentatively accounted f'or.

Now an alternative explanation offerecl for series A f'or

the relatively small increase in rate constant with pressure for compound I I I as compared with compounds I and II, was an

increase in cross-conjugation between the metho:xy gr•oup and the

cyano group. This factor was also one of two possibilities introduced to explain the greater reactivity of VI at

atmos-pheric pressure. (P ,.tiS). now ever, this factor were a major

one, the nitro group could not be displaced far from the plane

of the benzene ring., Furthe:t'"'more, an inel"'ease in pressure would increase eross-eonjn.gation effect and decrease the activating ability o:r the nitro g-.eoup.. s, however, not

the ease and it concluded that the

cross-conjugation :factor, at one bar and so under pressure~ is not

a major one.. Thus it is now that at one bar the

methoxy group has slightly greater effective, aterie deactivating influence than the methyl g:t'~OUp and hence that the rate

as to

eourse predicted

thus in Table

are plotted in F 10.

Br

0

N 01- NOz.

VII

) k.x104 _kp/k1

1 02 1

6 ..

31+

14

1 19 .. 53 9 ..

1 51 .. 69 6

~ 104 ~

seen that the

than for

OOlTIPG)Uilld VII it

.~;·~~:.o.u, ~

paper 1 06 ,

of tbe d

for

ion

, it woulc:t

results, ion. The

kr:/k1 values

7

VIII

kx104 0 .. 154

0 .. 258

0.368

0 .. 507

0 .. 797

1 ..

64

1

1

1 ..

2 ..

3 .. 17

3.03 19 .. 70

1

of product

the:re may some

However, in :fact

complex, ~u:~e

:to data are th1:•ee compounds

Br

A

NO~

NO~

C2.Hs

d+

_kp/k1

0 ..

573

1

1 .. 061 1 ..

84

1.,88 3.

3 ..

09

5.39

4.49

7-87 10 ..

7 ..

1

14

:posit

ring.,

by the introduct in molecule,.

acid, already out of the significantly further out

of' a nitro into

5-COOH

H0CI

NO~

out of plane attribute to buttress-ing of bulky nitro on hydrogen in the

6-position. A similar s been observed

m-dinitro-where nitro groups are out of 107 ..

swne effect

posit to one another are g~ite

11/i th be forced

incn:"ease

are two aetivat

the ion

say, COi11pou:nd

pressure the

sure groups o.f VII a

Since there

i tuents in compound VII the fx~om

spread over a nmeh wider area than increased solvation brought about

more

a the

to

ion site than a J!""'nitro substituent, combined

s of two in

127

Turning no'~;t to compound VIII (see Fig.., 10) , the

at a:ppear to be reasonable explanation. However,

the kinetics of 0 are

as

determined ( i. a .. "

the assumed is actual reaction k values),

a tentative explanation may be offered.., The e;x:plana.tion~ ieh is eurnbel"sorne and put :forward with little confidence,

is a.s follows.. the of increase of rate

ant at 1500 - 2000 bars some new effect. not

1500 It be post·u.1ated the u.::r•ucuJ,.,..

red:uction, brought about

in pressure,

may cause tlle nitro groups to be forced into plane the

the methyl group be someviha.t out of

1500 .-. 2000 bars. This would ue1:>m1

of somewhat change in

the

nkp,/k

₁ v

reaction rate

the initial

pu

curve

one of

compound VIII ..

for VIII for

less

should be

the

IX,

than for

effect

The opposite situation must be sought.

hyperconjugative effect

ible one appears to lie in , for

important.

reaction rates one

bar, was

woulrl tend

form of'

gl"eater early

An in

stabi1ize the more

polar,

more hyperconjugat gt"'ou:p, e. the

(

2

ive

for the ethyl

for methyl is

curve

for

as

and this wou1d account the

..,.u. ... nu.~. in F 1 0

tor

compound VIII, as

The effects are in in

methyl gt"oup foreed

the hype:~?conjugative effect be

of plane, readilY behaviour

or

to reaction explanation for

VIII, although superficially sat

'-'~u 1

~Ji

_L~~

~1--i~Lf_

--

-~--I 0

~~-+-+~++-~---1-!-~ 1--

-1-I -1-I

· - - 1-[__-r

! - '-·

=·

~J+li

! -

!

-L~l

-+

r _{-, I}

r~--

~ _{jl. I} ftt~T

·.

I _'!"~==~=·

-- !

-I - - +t1~

!-f-- -1- - -

·

--~ . . . . - · - ·-. · ----~

~H>nr•T•~ing evidence

on similar

P(

1

1

below in series

other

XI

) k.x1o6

3 .. 07

4 ..

69 6 .. 90

9 ..

13.45 18 .. 55

24 .. 03

8 (see also

more

clearly

, for is not form a

1

are probably best in son

ituted

TABLE 8

kp/k1

1

1 "53

6-04

7 .. 83

I and IV ..

BrO/'

_-

'r-o~

₀

-06 _k:p/k1

1

7.

1.

77

10"' 1+6

1 17

1+.48

7 .. 07

I.t-1 ..

9.71

R-Dromoacetophenone, having the rate o:f' the

e behaviour are

of increase

on u at eric

seen from a model

by the

not

constant can of solvat

carbonyl

operative

This

ei'i'ects on

as such ..

It

[image:155.595.71.461.304.548.2]

129

smaller increase in rate constant for this compound.

The plot of'

k_p/k

₁ for )2-bromobenzo;phenone XII shows a

"diaeontinuityu similar to that observecl for cotnpound VIII .. li'or this compound it must that the reactivity is

on the orientation. of the carbonyl group with both benzene rings, and that system is sterically hindered from attaining a ion. It may be that pressure tends to increase coplanarity with greatest success above 1500

bars~ around which pressure the 11_{discontinuity}1

t oacu.ra. It would be of intet•eE~t to whether the

1

1 Ham:raett, ical Organic stryn, ill

Co. 1 New York, 1940, Chaptel"' 7.

Ellis, , Rutherford, Fischer and , J. Ohem ..

Phys .. , ,

176, {1959).

2

3

4

Evans and Polanyi, F Soc.,

.ll,

875~ ( 19 ),

ametn.n, ":Physico-chemical s ,

Butterworth's ifie Publications, London, 1

5

6

Reference

4,

P.

177 ..

Gurney, "Ionic Processes in

New York, 1 P,. 1

7

~~

_Brower, , ~T.A.,c.s

_{J.A.c. ,}

.. , .JlQ, _§1, , _, (1958) .. _{(19 ).,}

8 , J. :Phya. Chem .. , , 977, ( 1925) ..

9 , J,.A.o,.s. t , 2068, (1926) ..

; z. ' j 2 , 1 , (1913 .. ) ..

ana. z. .§1t, ( 1913) ..

10

c

11 and Gill, ~T. Phys.. , 740, ( 1954) .. 12 Korber,

z ..

phys .. Chem., , 212, (1909) ..

1 3 ]'ink , Ann. , , 481 , ( 1 8 8 5 ) ..

14.

z

jl ' 151, (1 ) ..

15 R er 7 ..

ill

, P .. 1

Co.,,

16 Bogoj 1

g:z

'I 457' ( 1 ) ~

17

18 ll'anjung, Z.

19 Brander

20 21

21, ( 1

23

c

, 673'1 ( 1894) ..

, C omrn., Phys.

' , 353, ( 1929 ).

'

(8),

F Soc.,,

.2.1,

1684, (19 ). tlaznanLn, Trans .. "'t ; 1475, ( 1953)"

, (1 ₎

_'

.. 8., , ( 1960) , ' 2L~ 7.

.30 31

32

36

stein, Fischer,

'

a, Phys .. R

131

in, 191

, 1960,

a, University of :r-rew z'"'""'"""..._.., ... , 1958.

, ;u,

'

(1953),

Inat,,

1

1 , (1

) •

, Chapter Ohernistryu,

946.

Methods

' 359 , ( 19 25 ) .. ·""'" ... '""'"'", .2§, 166, (1923).

ov.L.Lv.t-·₁ M. .. Thesis, University Zealand, 1955 ..

Ref'erenee

4,

104 ..

R

4,

P. 1

Hnd

Solutiom:;n 1

• "The Chemistry Ilileetrolyte

e:i:nholo. ing Co'll', York, 1950.

37

~l

Dippy _{' J ..}

_{c "}

1 ( 19 36 ) ' 644 ..

,

c.a .. ,

(1934~, 161.,

.r .. c .. s..

(193L~₁₁ 1888.

Lewis,

c,.s ...

~ 1 ), 3l~3. 38 40 41 42 47 50 d) e)

ei', Rev ..

'

Roberts, S.~.m1""v"''""

.3290~ ( 1

, Garbi

c.. '

(19 ), 1

Chern .. ,

,

lt-20, (1

).

'

19'1 t { 1 )

'

f (1951)"

,

Ree,. Chim ..

'

l~oble, T and

z

,

J .. A ..

o .. s .. ,

t Chem .. R

'

,

273,

(1 ).,

Appl ..

,

j, 171, (1

)

..

(1

).

'

.r ..

.c.

'

.1.2,

'I 6020, (1