Cationic Ir(I) complexes with bipyridine and phenanthroline. Nucleophilic attack on unsaturated co-ordinated ligands

INORG.

NUCL.

CATIONIC

CHEM.

LETTERS

Ir(I)

Vol.

COMPLEXES

NUCLEOPHIIIC

ATTACK

pp.

WITH

359-362,

1975.

Trieste

Printed

in

Great

AND P H E N A N T H R O L I N E . LIGANDS.

and A . C a m u s

and C N R Center,

34127

Press.

CO-ORDINATED

G.Zassinovich

of C h e m i s t r y

Pergamon

BIPYRIDINE

ON U N S A T U R A T E D

G.Mestroni, Institute

11,

University

of T r i e s t e

(Italy)

~eceived 30 December 1974)

The

comple~es

ligands

of

the

substituted

type

Phen;

norbornadiene easily

with

bidentate

chelating

CIr(Chel)(L-L)] L-L

=

(NBD))

+

(I)

N-containing (Chel

=

Bipy,

ci.s,ci.s-1,Scyclooctadiene

give

stable

Phen,

(COD)

pentaco-ordinated

or

adducts

(i)

i

(i) L = tetracyanoethylene

(TCNE),

acrylonitrile, in

contrast

bidentate

acetylene~

ethylene,

with

of

systems

salicylaldiminates,

other

neutral

or

K

found

8-aminoquinoline,

-acceptor

electrophilic attacks the

in

reactions

phenylacetylene occurs,

with

nucleophilic

shat

8-mercaptoquinoline,

to

so

solvents

between and

FUN.

that and

With of

of

the

small

molecules

complexes they

(I) the

and

359

We

report

hydrogen

whiJe

diolefin.

increases

their

here

acetylene,

alkynes

bond

with

nucleophilic

medium.

acetylide, double

(I) undergo

basic

complexes

formation attack

of

cationic

character, protic

(2).

co-ordination

power

monoanionic

(l,2-bis(diphenylphosphino)ethane,

o-(diphenylphosphino)N,N-dimethylanilJne) We

(FUN),

dioxygen.

complexes

chelating

fumaronitrile

of

FUN the

abstraction

favours co-ordinated

the

on

Britain.

360

Cationic Ir(I) Complexes

Adducts The c o m p l e x ethanol

with

precipitate

with

acetylene.

with

Elemental formulae

Phen, (II)

analyses

to

(3).

v

spectra (R

of co-ordir.ated

absorption

also

d o e s not react.

are H,

=

spectra at

occurs

same b e h a v i o u r .

(II)

maxima

an o r a n g e

The r e a c t i o n

the

or

in a g r e e m e n t Ph;

Chel

=

of the new c o m p l e x e s

1930 and

2077

which

acetylide

(Phen)

cm -~

clearly

and p h e n a c e t y l i d e

[Ir(3,4,7,SMe4Phen)(COD)C~CH] band

at

3280 cm -:

due to the

(CH).

the s t a r t i n g

(II)

adduct

react w i t h d i l u t e again,

The f o l l o w i n g

a trigona]

gives

(3,4,7,SMe4Phen),

The c o m p l e x

a sharp

Complexes

(III).

shows

The i n f r a r e d

2090 cm ~ C~C

respectively

acetylenic

NaOH.

arld i n f r a r e d

absorption

shows

adduct

[Ir(Chel)(COD)(CmCR)]

1957 and

in m e t h a n o l

diphenylacetylene

3,4,7~SMe4Phen

show

correspond

also

of solid

while

3,4,7~SMe4Phen).

or at

The y e l l o w

by a d d i t i o n

The c o m p l e x

and p h e n y l a c e t y ] e n e

[Ir(Phen)(COD)] C1 r e a c t s

with pheny]acetylene,

with

acetylene

Vol. 11, No. 5.

together

reaction

bipyramidal

HCIO4

with

in C H a O H

an h y d r i d i e

derivative

p a t h can be p o s t u l a t e d

structure

for c o m p l e x e s

to give

assuming

(II)

CH

JSi C

+

NNI/ +

--~ Ir_C=_C~

.. The

stability

of

(III)

acetylide

and

reductive

elimination

an

hydridic

1980

cm

is

anhydride

band

at

due

to

the

substituents of

2216

and

trans-position , which

acetylene. cm

/Ld

Its an

does

infrared

acetylide

of not

the permit

spectrum band

at

a

shows about

Vol. 11, No. 5.

Cationic Ir(I) Complexes

In the r e a c t i o n acetylene alkynes

of the c o r r e s p o n d i n g

and p h e n y l a c e t y l e n e

occurs.

acetylide

an i m m e d i a t e

partecipate

Adducts The c o m p l e x

yellow

with

solution,

gives,

With dilute

yellow

HCIO4

the

however,

of

that

of reaction.

FUN

in the p r e s e n c e

from which

with

polymerization

to this kind

[Ir(Phen)(COD)j + reacts

product

standing.

Rh d e r i v a t i v e s

It is not to be e x c l u d e d ,

intermediates

The w h i t e

361

in m e t h a n o l of solid

crystals

starting

w i t h FUN.

NaOH,

a

precipitate

adduct

on

is o b t a i n e d

again. Analogous with

Bipy,

complexes

4,7Me~-~

Elemental complexes bonds

can be p r e p a r e d

5,6Me~-~

analyses,

~cate

the

of COD u n d e r w e n t

3,4,7,SMe4-Phen

infrared

(IV), w h e r e

a nucleophilic

[

__/

Phen

or COD w i t h NBD.

and N M R s p e c t r a

structure

FN

by s u b s t i t u t i n g

of t h e s e

one of the d o u b l e

attack.

OCH3

T

!

(IV) All 1060-1080 The N M R

cm

infrared

attributable

spectra

of the

show three methyl methyl

groups

the -OCH3

protons

comparison

to the free

and to FUN are

co-ordinated

molecules.

unequivalent

structure.

Nucleophilic

relative

ligands,

by a c r y l o n i t r i l e

occurs

singlet

shifted

also w i t h

at 7~i ~ at a b o u t 3).

protons

even

6.6 L

for

fields,

for t h e s e a complete

if FUN

is

(in the l a t t e r

the R h c o m p l e x e s ) ,

in CDCI~

The s i g n a l s

have

(4).

due to the

to h i g h e r

as is normal

or TCNE

vibration

derivatives

intensity

are o b s e r v e d

in the r a n g e

stretching

centred

The a r o m a t i c

attacks

a band

5,6Me,-Phen

a doublet

(total

to a l k e n i c

reaction

4,7 and

peaks,

show

to t h e - C O R

of P h e n and a sharp

protons

substituted

spectra

whereas

case the the

due in

362

Cationic Ir(I) Complexes

ethylene We

adduct wish

reactions,

to

does

not

point

although

react.

out

that

facile

for

for Rh and Ir(I) derivatives

Acknowledgement

Vol. 11, No. 5.

- Financial

these Pd

nucleophilic

and

Pt

attack

complexes,

are

unusual

(5).

support

by

CNR

(Rome)

is

gratefully

acknowledged.

References i. G.MESTRONI, A.CAMUS, and G.ZASSINOVICH,

J.Organometal.Chem.,

7__33, 119 (1974). 2. G.MESTRONI, A.CAMUS, and G.ZASSINOVICH,

J.Organometal.Chem.,

6__5, 119 (1974) and references therein; G.ZASSINOVICH, G.MESTRONI, and A.CAMUS, J.Organometal.Chem., RAUCHFUSS and D.M.ROUNDHILL,

in press; T.B.

J.Amer.Chem. Soc., 96, 3098

(1974).

3. D.M.ADAMS, Metal-Ligand and Related Vibrations, p.187, 212, Edward Arnold, London

(1966); P.M.MAITLIS, The Organic

Chemistry of Palladium, p.61, Academic Press, New York and Lonaon

(1971).

4. R.N.HASZELDINE,

R.J.LUNT,and R.V.PARISH, J.Chem. Soc.(A),

3705 (1971). 5. R.N.HASZELDINE, R.J.LUNT, and R.V.PARISH, J.Chem. Soc.(A), 3696 (1971) and references therein.