Anionic tricarbonyl derivatives of molybdenum and tungsten and their reactions with allyl halides

427

Journa1ofOrganometa11icChemistry.156 (1978) 42'7-437 0 ElsevierSequoiaS.A.,Lausann e-FkintedinTheNetherlanck

ANIONIC

TRICARBONYL

OF MOLYBDENUM AND

THEIR

BRIAN

School

AND

REACTIONS

TUNGSTEN

WITH

J.BRISDON, and

DERIVATIVES

ALLYL

DENNIS

JAMES

H4LIDE.S

A-EDWARDS

W.WBITE

of Chemistry, University of Bath, Bath BA2 7AY (Great Britain) (Received

?Iay 17th,

1975)

Summary A series where

I = Mo

or W,

of carbonylmetallate X = Cl,

or 2,2 '-bipyridine(bipy) cis-M(C0) was

L 42

evident

have

the

formation

with

various

ally1

I and

been

No

complexes.

evidence

for-

from

of -fat-to in MeCN

the

solvolysis Reaction

halides

yields

resulted

in high The

the mechanism

of the

significance

ally1

corresponding

mer-isomerisation

of fat-M(CO)2L2(MeCN).

[MX(CO)2(~3-RC3H,)L2].

servations

fat-[MX(COl2L,]-,

L2 = l,lO-phenanthroline(phen)

prepared

although

on dissolution,

with

complexes

Br or

anions

of

occurred the

anions

of q3-ally1 of

these

oh-

oxidative-addition

reaction are discussed.

Introduction The synthesis

use

reactive

of organometallics

well-established which

of higbly

these

procedure

nucleophiles

carbonylmetallate

of the [1,2].

react

with

early Because ally1

transition of

anions metals

the mild

halides,

many

for

the

is now

conditions new

a under

T13-ally1

428 complexes

of these

including

some

elements

chromium

have

analogues

CMX
materials

the

anions

been

for

of the

where the

facile

first

ceq.1).

anions

(eq.2).

not

given

subsequently

found

this

of

[3-71,

X = halide

this

prepared

A more but

route

VI series

or W and

synthesis

[MX
by

Group

I = MO

frown M(C0)3
prepared

series by

The

of allyl-complexes

Behrens

convenient

full

LS].

et al.

[9)

routetothese

experimental

details

were

173.

M(C013cht

+ bidentate

M
paper

molybdenum

and

preparation

+ X-

f X-

reports

tungsten

-

the

[YX(CO)3bidentate]-

LMx
anionic

of several

-

ally1

and

derivatives

and of

(1)

+ CG

ssctroscopic

complexes.

+ cht

(2) properties

filustrates

these

their

of

use

the

in the

elements.

Experimental Al2

solvents

in an atmosphere where

M = MO

prepared Ph4PC1 Ph4PX

by

were

of dry

or W;

purified nitrogen

and

dried,

gas.

The

L2 = 2,2'-bipyridine

literature

methods

by a stoichiometric (X = Cl or Br)

and

Et4NX

was

XI, while

(X = Cl,

were

materials

carried

Br or

precipitated commercial

I) were

were from

samples

warmed

out

&-M(CO)4L2,

l,lO-phenanthroline,

Ph4PI of

reactions

starting

or

[lo].

quantity

and

aqueous of

in vacua --

before

use. %I NMR

spectra

tetramethylsilane on a Hilger

as

and

Far

interferometer

Preparation

of

These with

Ph4PX

[MX(CO),L,]-

or Et4NX

mulls

studies

samples

complexes

Infrascan

Nujol

infrared

with

reference.

H 1200

using

on a JEOL

recorded

internal

Watts

spectrophotometer

or CH2Cl2.

were

were

dispersed

100

Infrared and

and

PS

spectrometer

using

spectra

were

on a Perkin-Elmer

237

solutions carried

of complexes

out

in pressed

recorded

in MeCN

on a Beckmann

polythene

FS 720

discs.

salts

were

prepared

by

the

direct

in MeCN

/toluene

or MeCN/xylene

reaction mixtures.

of cis-M
429

procedures

are

significant

given

for

variations

one

molybdenum

in experimental

Ph4P[MoC1(CO)_phen]. Mo(CO)4phen in refluxing product dried

4:l

was

Yield

in vacua.

by similar

time

For

of 4 h. was

the

(5 mmol)

product

was

in refluxing

filtered

analogous reaction 1:l.S

time

for

and

the

Preparation

of

The

washed

for

was

heated

with

Complexes complexes ratio

of 1:3

R4Z[MX(CO)3L2]

(10 mmol)

(1 mmol)

(0.2

h for

MO and

the

solid

product

was

filtered

off,

washed

with

Ph

known

of

gc

2) crystallised

to stand

L2

in over

Preparation

XIII

a

divided for

water, were

the

8 h.

then

The

methanol

prepared

1 required

at 0°C

complexes = bipy 80%

for

(10 cm3)

added

complete

(Table

in methanol

was

was

isolated

and

prepared

in an

a 16 h.

and

iodo-complex

chloro-analogues.

reaction

X = Cl or Br;

and

were

finely

(40 cm3)

for

the

The

with

in Table

When

allcwed

XII

ma~ol)

the

methanol

V (Tablel)

XIV-XVI

halide

was

(1.5

[Mx(c~)~(T~-Rc~H~)L~]

complex

XXIV

cold

ice-cold

of ally1

Complex

Ph4PCl

On cooling,

1 h.

IV and

and

below.

with

of complexes

rapidly

remaining

and

reacted

xylene/acetonitrile

a M(CO)4L2:R4ZX

bromo-

noted

a little

II,

(1 mmol)

Yield 93%. The

manner.

with

synthesis

8:l

off,

end dried in vacua.

was

complex,

necessary.

Et4N[WI(CO)3bipy-j.W(CO)4bipy Et4NI

rapidly

tungsten are

(40 cm3)

Complexes

97%.

procedures.

reaction

(1 mmol)

washed

off,

one

details

toluene/acetonitrile

filtered

and

only

slowly

72 h prior

yields

by

at ambient 1.0

and

the

where

M = W, X = Cl or

this

temperatures.

h for W compounds),

methanol and

solution

dried

reaction

in vacua. --

mixture

to filtration.

[MX(CO)2
to a stirred

Li'j~ bipy,

I [11,12]

were

M = MO,

all

procedure.

[MoBr(CO)2(r13-cyclohexenyl)bipy]

MoBr
3-bromocyclohexene

CO.5

(5 mmol)

(complex

XXII,

Table

vacua.

Yield

42%.

2) was The

mmol)

was

added

in CHC13

(5 cm3)

filtered

off,

corresponding

to a deoxygenated

at -15@c.

washed

with

phenanthroline

The CH2C12 anion

solution

product and

dried

reacted

3

in an

of

431 analogous

manner

oxidised

and

but

could

the

not

h3 -cyclohexenyl

be obtained

derivative

so

formed

in an analytically

pure

easily

was

state.

and discussion

Results

Tricarbonyl anions [MX(CO)3L2]The anionic yields

as deep

to reform were

most

and

of


purple

the

as

Sparingly

were

which

the

1 were

which

all

slowly

decomposition

data

were

in high

decomposed

on standing The

solvents

by coordinating

confined

obtained

products.

in non-coordinating

solvolysed

spectroscopic

of stoichiometry may

ligand.

should

stretching

give

exist

rise

Such

state

complexes

as

solvents,

to solid

the mer-isomer

case

three

strong

bands

are

expected

show

three

strong

CHCl 3 and

consequently

measurements

this

L

2

was

these

complexes

the

no evidence

on dissolution

NMe4[MoI
and

constant

Cotton-Rraihanzel

are

and

of

as

for

the carbonyl

as modified

by

anionic

state

forlner

and

two

and

in solution assigned

temperature

the

with

carbonyl

species

of any where

halide stretching

were

discernable.

the anion previously

a

the anions

solutions

saturated

strong

discussion

[M(COj3(MeCNjL2],

of

reported

in any

of

for

[9].

anions

Dalton

under

and

mer-isomerisation in MeCN,

weak

of MeCN

In MeCN

the

in the

consequently

spectra

of

be distinguished

one

at room

be retarded

both

carbonyl

since

solid

[Ni
data

method

and

[14].

solvolysed

of -fat-to

31,

solvents

could

may

anions

characteristic

or phen

reaction

in the

forms,

terminal

whereas The

infrared

features

= bipy

of both

There


Thus

showed

solvolytic

frequencies

[13].

is a bidentate

isomeric

measurements,

absorptions

solvents

L2

fat-isomer

predicted

latter

carbonyl

solvolysed.

or W and

are

In coordinating

the complexes

I = MO

the

two

the

intensity

absorptions for

of

where

infrared-active

In general

fat-configuration. quickly

in either

by band

in non-coordinating

[MX
to three

vibrations.

from

ion,

solids

of

soluble

in Table

3).

chelating

of

one

immediately

Complexes

were

listed

crystalline

cis-M
at most

CH2C12

complexes

were

et al.

calculated [15].

by

the

In previous (Continued

on p.434j

(XXIV)

all

38.0 (39.5)

78

txxrrr)

b

Known complexes

on Nojol

44.8 (43.4)

89

(XXII)

LMoBr(CO),(TJ-C,H,)bipy]

a Recorded

47.1 (46.1)

42

(XXI)

[MoBr(CO)2(q-l-MeC3H4)bipy]

[WCl(CO),+2-.MeC,H,)bipy]

42.2 (43.4)

82

(XX)b

46.7

mulls,

83

bands

(48,2)

[MoBr(CO)2(q-l-MeC3H4)phen]

90

(XIX)

86

C

[MoCl(CO),(U-2-MeC,H,)bipy]

)b

(%)

(XVIII

Yield

[MoC1(CO)2(‘I)-2-MeC3H4)phen]

Complex

are

strong

G)

unless

N

otherwise

Elemental analysis found (calcd.) (%) H

ANALYTICAL AND SELECTED INFEARED DATA FOR THE COMPLEXES [MX(CO),(q-allyl)L,]

TABLE 2

noted

1918

1928

1920

1920

1925

1925

1923

*1

Infrared v(c-o)a

1841

1840

1838

1831

1838

1636

1847

B1

data

(cm-l)

268

164

166

164

168

267

266

v(M-X)

433

TABLE

3

SELECTED

INFRARED

Complex

V(h+X)

AND

FORCE

(G-1)

CONSTANT

-1

v
FOR

A"

1765

1742

1880

II

146

1886

ANIONS

Carbonyl constants

A'

227

CARBONYL

1

Ai

I

III

DATA

K

1751br

force (mdyne

b 2-l)

Kc'

KI

K2

0.59

0.60

12.9

13.4

0.50

0.70

12.9

13.4

c

1884

1764

1742

0.60

0.63

12.9

13.5

IV

227

1887

1769

1748

0.59

0.62

12.9

13.5

V

153

1886

1772

1751

0.57

0.60

13.0

13.5

1884

1763

1740

0.61

0.63

12.8

13.5

VI VII

234

1874 1880

1764 1760

1743 1743=

0.55 0.56

0.57 0.62

12.8 12.8

13.4 13.4

VIII

147

1874 1880

1766

1743br 1745c

0.48 0.57

0.68 0.59

12.8 12.9

13.2 13.4

1746br

o.i7

0.67

12.8

13.3

1875

IX X

230

1877

1763

1743

0.56

0.59

12.8

13.4

XI

158

1867 1879

1753 1758

1736 1742c

0.54 0.56

0.60 0.63

12.7 12.8

13.3 13..4

XII

229

1879

1763

1719

0.53

0.75

13.0

13.5

XIII

222

1884

1766

1737

0.45

0.64

13.2

13.7

XIV

129

1900 1892

0.59

177?

xv

129

1899

XVI

127

1870 1881

XVII

125

1877

Recorded Calculated Solution

data

0.60

0.63 0.64

13.0 12.6

13.6 13.2

1756br

0.51

0.72

12.7

13.2

0.64 0.51

0.62 0.62

12.8 12.9

13.5 13.4

0.74

0.60

12.7

13.4

1747 1762

1726 1752= 1737br

on Nujol by

1778br 1751c

the

mulls

unless

procedure

in CH2C12

otherwise

given

indicated

in ref.15

434

studies Lewis

of cis-L -2 base

used

and

in such

K2 greater expected

M = go

derivatives,

3

from

where

or W [14,15],

calculations,

than

complexes

YM(CO)

the

resulting

the

equatorial

simple

n-bonding

cis-MnX(-CO)3L2

L = bipy

assignment

in axial

CO stretching

A'

>

force

A**

force

constants

However,

an electronegative

Y = monodentate

A' >

CO stretching

considerations_

containing

or phen,

as

some

halide

been

constants

$,

for

has

manganese

ligand

X *'i

becomes

larger

intermediate under of

than

frequency

consideration

this

band

order

force

but

Kz'$'

that

A' >

and

hence

the

calculated

magnitude

interaction

possible

VII

based

on

the

alternative

stretching

seems

3 with

Kc =-, Kc

constants<6

assignment

and

in Table

given

at

derivatives

possible

yielded

to those

band

VI complexes

Group

considered

calculations

to the

Group

neutral

were

also

divergent

assigned

the anionic with

These

second

nor

'i

tungsten found

to

these

complexes,

of

these

Group

charge

on the

significant

for

less

as

likely

low

as

than

varies Thus

probably

central

atom

Lewis

and

complexes

was

found

M-X

stretches

complexity

of

of the

Y = monodentate

On ally1

The

for

far-infrared each

of

of the

oxidation, in their

difficultto

base

throughout

effect

pentacarbonyl of

effect

the molybdenum

where

halides the

into

halogen [18]

increased

not

the

where

extend

increased

compared or phen

cis

radii

results

constants

fac-MX
does

of

or W. L2 = bipy

and

on the

covalent

C 2~? orbitals

force

M = MO

~ld,lS,lS]

of the

of back-donation

the anions

in a with

and

M = Mn

or Re

[16]. region

the anions corresponding

the M(I1) far-infrared

assign

marked

CO stretching

fat-MY(C0)3L2,

In the

the

as a result

VI elements.

X = halide,

significantly

2

the manganese

decrease

neutral

K

series.

Co group

more

were

A'.

widely this

Since

been

tabulated.. Neither

many

constants )

has

assignments

of a similar

with

mode

isoelectronic both

A"

constants

0.331,

are

force

the A"

Cl+17-J.

stoichiometry,

consequently

or

K2 and

with

only (Table

a single 3),

strong

at even

halopentacarbonyl

derivatives

so

spectra

and

confidence.

The

lower

wavenumbers

anions

formed M-X

halogen-sensitive

showed

stretching

most

halogen

[MX(CO)5)an

band than

the

c20].

increased

frequencies sensitive

were bands

435 the

in

entire

Table

2 and

are

tentatively

agreement

with

the

v
ratio

spectra

infrared

data

the

: v(M-Br)

frequencies

Ally1

at

derivatives The

halides

at

room

are

139

-1

cm

anions

given

in

are

in good

derivatives

with

thatof

were

show

are

also

strong

the

[Zl]

parent

examined

and anions,

to

stretching

W-I

respectively.

listed

temperature 'Ihis route

complexes

in Table

or below

1 reacted

to give

is particularly

to prepare

difficult

molybdenum

phosphine

closely

I and

XXIV

[?d~(~O)2(~~~-allyl)1.2]

carbonyl

derivatives. which

and

ditertiary

Br and

-

These values

[WI(CO)2
X = Cl,

137

XVIII

as v(M-x).

correlates

and

series

complexes

assigned

on analogous

[WI(CO),(?i-C3H~)bipy] c complete

of

by

[11.12]

due

the

high

useful

slow

yields for

procedure

to the

readily

ally1

of M
the

tungsten

normally

kinetics

with

analogues

adopted

for

and

competing

and

XIX

the. reactions

_ of the

tungsten

sufficiently showed due

intermediates.

soluble

singlets

to the

8.25(d). ally1

for NMR

at

6 1.01,

n3-ally1

group,

8.06(t)

methyl

and

group

Only

measurements.

1.40

and

and

7.61(t)

ppm

The

caused

by

is even

greater

(6 0.70

related

complex

[Mo(NCS)(CO)2(?l-2-MeC3Hq)phen]

shown

to lay

solubilities precluded' CkC

of the their

stretch

this

members

the

and

plane

of

the

complexes

solid-state

with

mechanisms halides

of

complex

this

methyl

in Table

2 in suitable.

XVIII

structures

and

and

XIX

shift

closely

group

[22].

The

has

low

NhlR solvents

of an uncoordinated their

and

[22,23]

the

the

In the

ligand

oectra

of

effects

ally1

the absence

3:2:2

6 8.79(d),

shift

aromatic

infrared

known

at

group). the

latter

ratios

up-field

shielding

were the

intensity

absorptions

methyl

but

to complexes

at -57OC

phenanthroline

the ally1

characterisation.

q3-ally1

related

for

remaining

stoichiometry of

the

similarity

Various ally1

full

in their

spectroscopic of

over

corresponding

the

ring,

ppm

with

pronounced

aromatic

been

in the

2.39

ppm.

XVIII

In SO2

2,2'-bipyridine

is no doubt

and

complexes

to

general other

indicated

complexes

they

were

also

series. have

been

proposed

to low-valent

for

transition

the

oxidative

metal

addition

complexes,

of

including

436

nucleophilic [241p

attack

a concerted

and

initial

step

[27].

ally1

of

the metal

insertion

coordination Strong

mechanism

of

the

a-C

atom

thp

anion

subsequent

of

the

evidence


that

or direct halide

of halide

carbon

[25], to the

atom

bearing

a radical metal

chain

as

the

the.balogen process

rate

last

mechanism

is operative

has

been

presented

recently

(B), in

would

attack

in the A

[28].

metal

atom

on

explain why the halogen in

the P(II)-ally1

occurs

of the

[ZS]

determining

this

nucleophilic

retained

is initially exchange

e:C

systems

ally1

the

reaction

halide-IrX
similar

at

in some

products,

instances

although

in solution

on

standing.

A

+

[Mx(co)3L21-

CH2=CH-CH2Y

-

[(YcH2cH=CE2MX(co)2L2]-

I cMX(co)3L2]-

+

c!B2=CR-CB2Y

-

'co

fast

mwo)2L21 + y-

[ (R-C3H5

B

+

~~cH~=C~-CB~)MX(C~~~L~I

+

Y-

fast I [&C3"5MX

Attempts have

proved

to identify

unsuccessful

positively

so

either


of

these

+

reactive

CO

intermediates

far.

Acknowledgement We

thank

the

S.R.C.

for

the award

of a Research

Studentship

References

1.

J-Ellis.

2.

R.B.Mng.

3.

G.Doyle.

4.

J-Ellis

J.Organometal.Chem.. Acc.Chem.Res.,

86

3 (1970)

.J.Organometal.Ghem., and

R.A.Faltynek.

132

(1975)

1

417 (1977)

243

J.Organometal.Chem..

93

(1975)

205

(to J.W.W.).

437 5.

M.Schneider

6.

F.Hohmann,

7.

B.J.Brisdon

and

G-F-Griffin.

J.Chem.Soc.Dalton

8.

B.J.Brisdon

and

G.F.Griffin.

J.Organometal.Chem.,

9.

H.Behrens.

and

E-Weiss.

J.Organometal.Chem..

J.Organometal.Chem..

E.Lindner

and

137

(1977)

G.Lehnert,

(1974)

C7

315 (1975) 76

1999 (1974)

J.Organometal.Chem.,

M.B.H.Stiddard,

11.

C.G.Hull

12.

H.

13.

L.E.Orgel,

14.

L.W.Houk

15.

J-Dalton.

I-Paul.

16.

L.F.Wuyts

and

17.

R.J.Angelici,

18.

M.B.Hall

and

R.F.Fenske,

Inorg.Chem..

19.

L.W.Houk

and

G.R.Dobson.

J.Chem.Soc.A,

20.

R-J-H-Clark

21.

B.J.Brisdon

22.

A.J.Graham

and

R.H.Fenn,

J.Organometal.Chem..

25

(1970)

173

23.

A-J-Graham

and

R.H.Fenn.

J.Organometal.Chem..

17

(1969)

405

24.

P.K.Wong,

25.

R.G.Fearson.

26.

J.A.Labinger,

27.

J.A.Osborn.

tom

Plenum 28.

M.B.H.Stiddard,

Dieck

and

G.R.Dobson,

der

F.Easolo

and and

and

J.Chem.Soc.A.

Inorg.Chim.Acta

A.J.Poe,

23

19

85

(1963)

J.Amer.Chem.Soc., 11

(1972)

(1966)

J.Organometal

Chem.,

149

in Y.Ishii

and and

Corp.,

A.T.Poulos

and

J.A.Osborn,

M.Tsutsui

New

J.Amer.Chem.Soc., 41

York,

J.A.Ibers,

(1973)

(1978)

96

113

(1974)

5956

76

J.Amer.Chem.Soc.,

(Eds),

2215

317

K.E.Paddick,

Fortschu.Chem.Forsch.,

1208

1619

224

J.K.Stille,

(1968)

(1977)

(1969)

A.V.Kramer

.

375

2119

J.Chem.Soc.A.

and

519

(1968)

B.C.Crosse.

K.S.Y.Lau

Publishing

14

5 (1966)

F.G.A.Stone.

Kelen.

and

665

25

Inorg.Chem.,

J-G-Smith

G.P.Van

9 (1969)

J.Organometal.Chem.,

1 (1962)

(1970)

4712

J.Organometal.Chem..

H.Friedel,

Inorg.Chem., and

J.A.Kaduk,

(1962)

C47

22

10.

and

J.Chem.Soc.,

73

95

(197'3) 7908

Organo-transition.Metal

Chemistry,

1975. J.Organometal.Chem..

127

(1977)

245