gold(III) oxidative-addition

1NORG.

NUCL.

CHEM.

LETTERS

Vol.

11,

pp.

363-368,

1975.

Pergamon

Press.

Printed

in

Great

Britain.

H A L O G E N SCPC~A~BLING IN GOLD(1)/%GOLD(II I) O X I D A T I V E - A D D I T I O N B.T. H e a t o n

and R.J. K e l s e y

UT:i-~ers'ty C h e m i c a l L a b o r a t o r y ,

Canterbury,

Kent.

CT2 7NH

(Received 3 January 1975)

Ox~datlve-additior~ --- . . . . , - ~ r l l )

ccmp!exes

of bromir:e to s q u a r e - p l a n a r ;vas fou:u:~ to r e s u l t

of ~h~or ..../brom-_L. and formation ~omp!exes

• thcuE~

_ ~ - -' y ....

reports

Ve no,~ report

of all siz isomers

solution

a-~signm,~ t of the spectrum,

systemst~.-0

equslly

2,. ~)o.3

of chlorine

complexes, 2

(i tool) to [AuBr(PEts)]

at 25 o r e s u l t s

5n the r a p i d formation

(see which

consists

spaced lines,

trends observed "

- x

( y = O. 1 , 2 , 3 , 4 ,

~a)L-

from a comparJson

with

(X = Ol of Br) and f'rom -~hc

u
~,

5 ) 15 and [ P t B r 3 _ a C l a ( P E t a ) ] -

Th;~ . . ..... . ..,~. two sets of r e s o n a n c e s

or br,s:~ln<-- b~i up, trots to the p h o s p h i n e

363

ig.1).

of two sets of three

follows

s~th~T:tic [A~X3(PEt~)]

-'~

of s q u a r e - p l a n a r

of linear

b:;

the ~p~ztra c f

of interest

of the type [ A u B r s _ a C l a ( P E t s ) ] (a = O, l, 2 and

z)

apprcz'mDtely

L = PRs, PY or

s u g g e s t e d this not to be the case.

that a d d i t i o n

('i tool) "n ch]oroform

(PEte)]-

reactions

scrambling

p2atznum(!V)

It was therefore

occurred upon formation

complexes by c x ~ d a t i v e - a d d i t i o n even

(R = Etp Bun;

(py = pyri~ine). I

to see if scrambli:,

in a s t a t i s t i c a l

of the octahedral

trans [PtB~_xCi~_x(PR3)L]

s u b ~ t i t o t e d py)

trans-dlchloro-

are due

and

of chroride ~"J _y

(a = O, .';., to either eb.!or!ne

the three r e s o n a n o e s

364

Halogen Scrambling

VoL 11, No. 5.

w i t h i n each set are due to a p r o g r e s s i v e cis to the p h o s p h i n e b~r b r o m i d e There

~dth

on w h e t h e r

relative

the chloride

(see Fig. 2).

the p L a t i n u m ( I I ) a n a l o g u e s

F o r a statistical

the total e l e c t r o n e ~ a t -

in the complex a n d 6P, w h i c h is

found to d e p e n d only s l i g h t l y to the p h o s p h i n e

of chloride

(see Table)°

is a good c o r r e l a t i o n b e t w e e n

ivity of the h a l i d e s p r e s e n t

or t r a n s

replacement

where

scrambling

ratio of e q u i l i b r i u m

This

should be

a much bigger

of h a l o g e n s

constants

is cis contrssted

dependence

the f o l l o w i n g

(see Scheme)

w o u l d be

e x p e c t e d K~: K~: K~: K~: Ks: K~: K~ = 2: 2: 2: 4." 4: I" I. o b s e r v e d relative

ratio

Ks: F~ at 25 o is 2.0;

2.5"

can be seen to deviate values w i t h

increasingly

scrambling

: 5.9~ w h i c h

from the s t a t i s t i c a l l y presumably

Similar results

The

K~: K~: }{3: K,: Ks

: 5.5:

substitution~

of A u ( l l l ) o 4

chloride/bromide

constants

2.5: 1 0 . 9 : 1 2 o 6

increasing bromide

class b b e h a v i o u r for

of e q u i l i b r i u m

is

expected

due to the

have b e e n o b t a i n e d

in trihalo(triethylphosphine)--

platinate(ll ) o 3

E x p e ~ i m e n hal

spectrometer.

~t 40.4789

i~ate~icchlcr)fc,_,m; quoted r e l a t i v e

to

L!}~z for solutions

ci~e~:icuJ shifts exter~nat -

sT'eeies ~ - V] (sc'e Scheme) DL ssalc Thc

were

6 _,,~ ~ H,~PO~ ~

i'~

(high fr'equcney +ve) ape •

The

C 0[1.%,--I~ . . t,~ . . a. t Z OTI$

eL

~i e

',vel~:~oOtaine,~.... }',~',,,mer~surin S peak ~"-~}s

<~xi:a~-ded slj;,ectpa sr.d ~r(!~ aeeD.r'~t:~ t,~ b.e-i
~f

?uX(]'Zt,:~)

o.~ <-~ , o , ~ , ) : { ( t S t : ~ ) ( X

carried out exactlL, t
analyses

of the complexes

agree

exactly with

,~;~ '~L(~ [,(:,!lin~ ~

those p r c v J ~ < ~ l . v

of 6p, obtained w i t h solutions

= C1 o r

fo,,~ S.

o/E

}3r%

,:~,-:

The values

co~,t:A]nJn:~< 15[) [:b[ o£ th~ comp]z&

Vol. 11, No, 5.

Halogen Scrambling

365

C1

C1

I Et3P

l

El

- A u - CI

Et3P

- Au

I

- Br

l

CI

C1 II

1Lx

I<

Br

BP

I

Et3P

- Au

I

K2

- CI

Et3P

- Au

- Br

l

C1

CI

III

IV

I< Br

Br

I

l

E t 3 P - A u - CI

Ka

w

Et3P

- Au - Br

Br

Br

V

v]

SCHEME TABLE

Chemical of the

isomer ~

i

6p

66.0

::

See

$

Shifts

Shifts type

III

~_

60.8

55.6

(p.p.m.)

for

[Au B r 3 _ a CI a

complexes (PEt3)]

I-~

__IV

VI

61.6

56.8

51.9

Scheme

to h i g h

frequency

of r e f e r e n c e

are p o s i t i v e

ISO'q~

Fig.

1

II III

IV

V

VI

refer to Scheme and Table.

(i mol) in deuterochloroform solution.

Isomer numbers

results from additio~ of chlorine (I mol) to[AuBr(PEts) ]

31p-~'H} n.m.r, spectrum of [AuBr3_ a C1 a(PEt 3)] which

I

Z o

?-

<

E

o

,4

6 Z

x

i

~'6

~'6

C'6

T 22L!.

+

i

~

I

;

-

~'6

~ I

T

u~ ~

; ~

:

"

+

I'6

•

+

'

"

• (~

I

"

'

.

"2+!:. ,E

+

.

.

.

. . . . . .

6"8

i'

•

i

i

x_........ i I:; +I

:_ii

I

+

-

++ . . . .

"

8"8

"~9

d9

"09

,--~,O~

] ......................

....

t ........ T ....

J

0"6

~@

'

, ..........

•

;.i_+i ...... . . I . . . .j.-il . . __;_;_~__L_L..........

i

l

0/.

368

Halogen Scrambling

in I ml of solvent, AuBr3(PEt3)

for AuCI(PEt 3]" , AuI~'(PEt +~ ), a.... . ~ 3 ~Et 3) and

are 31.7,

34.6,

the slight d i s c r e p a n c y

65.7 ~n~l ~].5

b e t w e e n 8p

(X = C1 or Br) and that observed (PEt3)]

p.p.m,

for authentic

It should be noted

of [ A u C l 3 ( P E t 3 ) ] s h o w e d a s i g n i f i + a n t present. as noted

This

is consistent 2 previously.

The p r e p a r a t i o n chlorine

chloroform

at 250 .

concentration 24 hours

constants

of L++~u+'~-+(]?E ++3)] +++ . . .++ .

the instability

of Au(1)

of thzs corn ou~d,

carried

out b~

of jAunt(PEt3) ] (i mol)

no significant

showed

of [AuBr3_aC] ~-

the 3'P-{~H}n.m.r.

amount

to a solution

of the isomers

th~ s p e c t r u m

concentration

with

that

The spectrum was recorded

after 3 hours w h e r e u p o n

[AuX3(PEt3) ]

I~ecause of conceutr~t~om

of LZuBr3_aCla(PEt3) ] was

(i mol)

respe~tivel~:

in the spectrum

(a = 0, l, 2 and 3) probably acises

differences.

adding

Vol. 11, No. 5.

change

~m!ediately

to be present.

anl

in the relative

I - IV had occurred. the presence

~

However,

after

of a significant

The relative

equilft rium

refer to the initial spectra.

REFERENCES

I.

B.T. H e a t o n

and K.J. T i m m i n ~ Chem.

2.

F.G.

~ann and D. Purdie,

3.

R.J.

Foot and B.T. Heaton,

4.

S. Ahrland,

J. Chem.

Comm., Soc.,

unpublished

J. Chatt and N.R. Davies,

931,

1235,

(1973). (1940).

observations. Quart.

Revs.

12,

265,

(1958)