Dimethylplatinum(IV) compounds. V. Preparation and reations of bis(salicylaldehydato) complexes

121

Joumol of OrganometalIic Cizemistry, 161 (19’78) 121-138 0 Elsevier Sequoia S.A., Lausanne - Printed inThe Netherlands

DIMETHYLPLATINUM(IV)

COMPOUNDS. V. PREPARATION AND

REACTIONS OF BIS(SALICYLALDEHYDAT0)

J.R. HALL

and

COMPLEXES

G.A. SWILE

Department of Chemistry, University of Queensland, Brisbane, Australia 4067. (Received

July

17th,

1978)

summa ry

Two geometrical

isomers of Pt(CHa)2(Sal)2 have been prepared and Some reactions of isomer A (phenolic

identified by 'H NMR spectra. and

oxygen atoms traj?s to CH3)

isomer

6

(aldehydic oxygen atoms t?%??s

Isomer B reacts with CgDaN to produce species

to CH3) are reported.

containing unidentate Sal in

while

solution,

Primary amines react with isomer

with formation of hydroxo species. B to form salicylaldimine

isomer A tends to lose Sal

complexes.

isomer A reacts with en to form

Pt(CHa)zen(DH)z.

Introduction Although a large range of f3-dicarbonyl complexes of both trimethylplatinum(lV) far

less

was

prepared

dimeric [g,lO]

[i-6]

and dimethylplatinum(lV)

work on salicylaldehydato

with

by

reaction

bridging

of phenolic

[7-81

complexes.

[Pt(CH3)31], oxygen

with atoms

are kno.,:n,there has been

A compound of formula R(CH;)3Sa' TiSal

both

in

is]

and k/as

the

solid

found

to

state

and in solution [ll], but no reactions of the compound were

reported.

In the dimethylplatinum(lV)

system only the compound

Bur+N[Pt(CH3)2Br2Sal] which is monomeric with Sal tzw?s to CHa groups has been reported 1121. geometrical

In this

paper

we report

the

preparation

of

isomers of formula Pt(CHa)2(Sal)2 and a number of reactions

be

122 these

of

have

compounds with

been

Results

reported

pyridine-dg

amines _

Preliminary

results

[8].

and Discussion

E'nzparatioz

and

identijYca-t;icn -L

Pt(CH3)2(0H)2-2H20 from

and

such

solutions

isolated.

The

is

in

soluble

decomposed

dissolves

a compound

product

is

organic

of the

in boiling

of

formula

by 95% ethanol

or

such

as

aqueous

salicylaldehyde

Pt(CH3)2(Salj2

an orange-yellow

solvents

Pt(CH313(SaZ)7

compozmds

may be

crystalline chloroform

acetone

and

to

and

reform

solid

which

benzene

but

the

hydroxo

cdmpound. Assuming three

bidentate

geometrical

salicylaldehyde

isomers

are

and &s-methyl

possible

for

Pt(CH;)2(Salj2

Fig. 1. Isomers of ci.s-dimethyl-bis(saJicylaldehydato),olatinum(IV),

The

‘H

NMR spectrum

presence

of

only

resonance

(with

and

(I

ruled

lg5Pt out

one sate1

= %,

since

of

for

the

isomer li tes

compound since due

34% abundance)) this

isomer

in

only

CDC13

is twc

(Fig.

a single

to coupling

groups

non-equivalent

(see

present,

Fig.

Pt(CH3)2(SaI)l_

2a:

indicates

the

methyl-platinum

between

observsd.

are

the methyl

Isaner

protons

C may be

methyl-platinum

-* The compound Pt(CHsj2 (OHj2;2H20 has been reported f rem the reaction df [Pt(CH3)2Br2] with NaOH ES]. Subsequent preparations indicate that freshly pre;ared samples approach this formulation, but there is loss of weight with ageing and the compound is probably better described as Pt(CH3)2(OH),nH,O(n=l-2).

lj

_

123

I

,

I

I

Fig. 2. ‘H n.m.r. spectra of Pt(CH,)Z(Sal)2

resonances to

the

influence

positions

of

Hz,

Table

atoms

trall.s

trmzs

to

to

phenol

CH3 tim?s

1)

in CDCI,;

(a), isomer A and (b), isomer B. *ThIS.

to

to

salicylaldehydato This

value

8 of

Fig.

is

phenolic

of the

(74.1

the

to

be

compared Hz)

be

expected

atoms

in

the

coup1 ing

wi th

appears

when

donor

would

presence more

with

and

constant

aldehydic

trays

observed

of

oxygen

consistent

the

due

donor

with

CH3

obtained

valties

Hz)

(78.6

in

[12]. Table ligands

substantially

1 (where

of tent

and

i c oxygens

BubN[Pt(CH3)2Br2Sal] Reference

consis

CH3 [13]

constants

types

magnitude

is

I

8

r

coupling

different

The

1131.

(72.4

for

different

with

’

I

6

1

4

2

0

the

1 shows

that

the

to

lg5Pt

couple higher coup1 ing

than

would

aldehydic with that

protons

of

the

a magnitude

of

121 .O Hz.

expected

be expected

to

for

either

be of

the

isomer same

124 TABLE ‘ii

1

NMR SPECTRA OF ISOMERS CF Pt(CH3)2(Sal)2

AND THEIR

Pt-CH3

P t-O=CH

Compowd r

T

J

REACTION

PRODUCTS

P t-N=CH *

J

Pt-N-CHs

J

T

J

In Ifi-dichlorobeozene Pt(CH3)2(Sal)2

In

A

a.13

72.5

B

8.12

77.5

C

8.07

77.2

a.23

72.7

A

8.23

72.4

1.83

B

a. 13

16.3 15.9

CDCl?

Pt(CH3)2(Sa1)2

Pt(CH3)+al

(Sal=N-CH;)

77.5

0.62

8.31

79-I

0.67

121.0

1.89

22.0

6.61

8.7a

1.95

22.5

6.67

9.1 6

I.83

19.6

6.58

y-1'

8.55

67.1

Pt(CH3)2(Ss1=N-CH3),

8-66

68.4

Pt(CH3)2(Sal)

a. 14

78.7

8.44

68.5

8.49

68.4

2.04

22.2

a.55

70.4

1.90

19.2

(Sal=N-C6Hs)

(Sal=N-CH?)

Pt(CH3)2(Sal=N-C6H5)

Pt(CH3)2(Sal)2,S

+ en:

Ini tiai Products:

8.32

78.8

a.52

66.6

a.&0 a.52

66.6

Major

8.64

68.6

Minor

8.65

69.0

Major

Minor

Final

In

Products:

79.1

0.68

15.4

1.83

Igd

0.61

15.2

1.93

20'7

1.92

21.2

c

CDCI~-CSD~N

Pt(CH3)2(Sal)2C+$~

Pt(CH3)2(Sal)z(C~DSN)~ Pt(CH3)2(Sal)

(CSDSN)OH

Pt(CH3)2(CSD,N),(OH), In

16.0

0.78

a.025

77-

a.57’i

71.6

-0.62'~

-

8.07

71.4

-0.48

-I

1

17.2

0.62’

8.3+

73.2

1.46

8.49:

72.0

O.Oy'i

8.63

71.8

8.87

70.7

76.2 -

D,O

Pt(CH;)zen(DH)z

(L d 5

3J (CHj-N=CH)

1.2

Error

’

~1

Slight

50% by

Hz.

Hz. Region

downfield

shift

g

Slight

volume. 50%

increased

to

increased

to 50%

’

by volume. by

volume.

1.4 Hz.

3J(CH3-N=CH) complex,

(3-4

Hz)

upfield IL

only as

peaks

(2

move5

Hz)

as

1.3 Hz.

identified.

CSDsN concentration

shift Peak

major

3J(CH3-N=CH)

=

increased

to

CsDSN concentration

to T -0.73

as CSDSN

concentration

125 order

as

[14]

since

Fig.

1

when

allowance

with

that

found

the

is

methyl

can

for

with

only

isomer,

be

[16].

found

it

for

assigned

to

heating

not

the

and

and

reactions

metallic

reported

this

below

for

more

orientation been

compounds

to

a particular

with

the

found

consistent

results

that

Hz

those

compound

can

be

1. is

indefinitely

stable

boiling

according

are

Hz

assignment

these

the

121

I)

of

of 40

in alken$lplatinum(l

unequivocal

compared

15 and

a favourable

al though

of

are

have

solvents

dicyclopentadiene

is

of

0

coup1 ings

couplings

evi dence, an

Fig.

terms

of

isanerA

of

the

CH3NH2

Hz)

be expected

influence

value

large

comparison

high

new species

the

to

usually

results

lH

dependent

such

in

the

by

state,

tetrachloroethylene,

in

the

formation rate

The

temperature

accompanied

solid

as

NMR spectra.

on

the

of

of

of formation

reaction,

some

decomposition

m-dichiorobenzene

solutions

to

platinum.

Accord (Table

i ng

l),

three Two of

Hz)

at

remain from is

in

than

was made The increased

NMR spectra

these

equal

species

isolate

third in

to

one-third

with

be

of

(T

8.07,

throughout

the

the

appear

J 77.2

C of

total

Fig.

species

during

Hz;

reaction

non-equivalent

isomer

T 8.23, and

methyl

1 in

but

the

so

J 72.7 probably This

groups.

was

never

solution

and

present no

attempt

it.

methyl-platinum intensity

resonances

resonances

intensity

postulated

to

of

new methyl-platinum

a single

species more

‘H

to

reaction.

arise

by

in

new species

these

Similar

compound

m-dichlorobenzene

of

in

above

A of

isomer

high

or

might

, where

CH3 and

(22-27

CH$

Hz)

tiqar?s 3+

to

to

( 0, 60

abnormally

isomer

solutions

several

tia7z.s

smaller

trans

allow

only

other

Al though

value

rationalized

The

is

the

is

case

H couplings

A.does

and

each

the

H groups.

Hz)

isomer

for

The

Pt*=C-

(120-148

[pt(CH,),Br,Sal=N-RI-

higher

protons

Pt-O=C-

trails

complexes

*[Pt(CH3)2(CH,NH2)4]-

[ 151)).

coupling the

made

(cf.,

respectively

of

in

a somewhat

[13]

methylamine

the

coupling

(where

CH3

in

as

resonance the

reaction

(T

8.12,

proceeded

J 77.5 and

was

Hz)

gradually

ultimately

126

the only such resonance present. species

a yellow

solid

analysing

From solutions containing this for Pt(CHx)z(Sal)z was isolated.

This

solid is soluble in chloroform and benzene and, in contrast to the previous

isomer, dissolves in ethanol and acetone without decomposition.

The IH NMR spectrum of this isomer in CDC13 is shown in Fig. 2b. The NMR data (Table 1) are consistent with this compound being isomer B of Fig. 1.

A single methyl-platinum

resonance is observed

with a coupling constant of 77.5 Hz consistent with CH3 trazs to oxygen donors [13] while the salicylaldehyde with lg%t

aldehydic protons couple

with a magnitude of 16.3 Hz, comparable with the coupling

of the aldimine proton in

[Pt(CH3)2Br2Sal=N-R]-

[lb].

It

may be

noted

that for this isomer there is no enhanced coupling of the aidehydic proton to lgsPt. Since the magnitude of the coupling constant gives an indication of tend strength

[13] it would be predicted that the coupling

constant of a methyl group i=rans to an aldehyde group as in isomer B would

be greater

than

that traisz to a phenolic oxygen as in isomer A.

The couplings observed for the two isomers (77.5

Hz for isomer B;

72.4 Hz for the initial isomer) tend to confirm that the initial isomer is isomer A.

Reactions of the compounds Pt(CH?)T(Sai)q

When CsDsN is added dropwise to a CDC13 solution of isomer B, two new methyl-platinum (Table

1).

resonances appear in the NMR spectrum

These resonances are of equal intensity and are presumably

due to a single species with non-equivalent methyl groups.

The

coupling constants, 71.6 and 77.1 Hz are consistent with methyl groups t~ans to CgDgN and an aldehydic oxygen respectively, so that

:‘:

CsDsN rather than CsHsN resonances to be observed.

was used to enable the aldehydic proton

127 the

species

and

one

is

unidentate

The

ligand.

presumed

to

be Pt(CH3)2(Sai)2(CSDsN)

the

(via

aldehydic

phenol

proton

ic

region

oxygen

atom)

supports

with one bidentate

sal

the

icylaldehyde

presence

of

such

a species since two separate resonances are observed, one at T 0.62 (J 17.2 Hz) which is attributable

to CHs and a second at ~0.62

group zkans

fi rst

to bidentate Sal with the aldehydic

and shows

no evidence

for

which

is broader than the

coup1 ing with lg 5Pt.

There

is

apparently an equilibrium between isomer B and this species

since

there

addition

is

still

an

appreciable

amount

of

isomer

B. present

on

of more than two moles of CsDsN per mole of Pt(CHs),(Sal),.

There

is no further change in the spectrum on allcwing the solution to stand.

On the other hand,the relative amounts of each species are

altered

by Further

changing

the

addition

concentration

of

Pt(CH,),(Sal)2(CsDSN),

CsDsN

of

results

slight changes

CDC13. in

in

increased the

formation

chemical

shifts

of of

the

methyl and coordinated aldehydic protonsand a more marked downfield shift of the free aldehyde proton which also tends to sharpen. Continued addition of CsDsN results in the formation of a new species with only a single methyl-platinum

resonance (T 8.07, J 71.4 Hz)

which is postulated to be Pt(CHs)2(Sal)2(CsDsN)2 trcvzs to CH3 and two unidentate salicylaldehyde

with CsDsN

(via the phenolic oxygen atom)

ligands. A single.sharp

resonance (T - 0.48) appears

in the aldehydic proton region with no evidence for coupling with 19Spt.

Further addition of CsDsN increases the amount of this species

at the expense of Pt(CH,)2(Sal),(CsDSN) species is present.

until only the bis pyridine

On allowing such solutions to stand for several

days decomposition apparently occurs,since

the colour of the solution

becomes deep red and the NMR spectrum shows a large number of new peaks in the methyl-platinum

region.

When a solution of isomer A is treated dropwise with C5D5N, two new methyl-platinum

resonances appear in the NMR spectrum.

The

resonances are of equal intensity and presumably arise from a single

128 species

with

constants tiazs to

observed

to

CsDsK

stand

in

platinum, isomer One

second

Two

position

cis

is

present

at

~0.09

chemical

(T

the

methyl

than

which

is

probably

shift

is

almost

the

more

species

yields

large

The due

0.06).

The

likely

from

121.0

with

the

Hz

in

in each

in isomer

arising

a change of

this

further

with

resonance Furthermore,

the

pattern

found

in

ligands

have

probably

of

aromatic

its

salicylaldehyde solution

could

with

CsDsN or

formulation containing

this

infrared

the

coordinated

species

is

orientation

spectrum. aldehyde

also of

effect

a second 8.63,

consistent the

would

region

to

of

the

sat icylaldehyde. and

the

solution

OH and CsDsN as

to

J 71.8

aldehyde

not

the

(Table

1)

aldehyde

proton

increases

in

spectrum

resembles

the

This

indicates

methyl-platinum for

give

a solid by

Hz)

exhibiting

T 0.06)

Support

confirmed

species

CSDSN while

(shifted

displaced

the

singlet

the

influence

(+

I%ZV_S to

Pt(CH3)2(CsDsN),(OH),_

by evaporation coordinated

been

a trazs

be

in a

a sharp

in

latter

this

can

salicylaldehyde

(CsDsN)OH

of

a particular

resonance

previously

free

in

and

platinum

for

solutions

constant

species.

since

present

of of

second

bidentate

in

mole

expense

Hz)

is

solution

magnitude.

CH3 groups

observed

of

Hz

the

the

per

the

to

found

The

CsDSN produces

methyl-platinum

consistent

76.2

from since

of

atom.

coupling

A to

that

OH vibrations

with

the

one

Pt(CHs),Sal

evaporation

compound,

Addition a single

since

a product

coupling

in

oxygen

for

bonded

species

or

at

salicylaldehyde

with

CH3 groups

CsDsN

resonance

free

to

lq5Pt(76.2

that

second

to

of

present

with

so

identical

(T

moles

group

groups,

aldehydic

decrease

are

coup 1 i ng

On allowing

increases

coupling

[Pt(CH3)zSal(CsDsN),If to

two

gradually

compound.

The

respectively.

more

shows

the

appears

result

of

groups.

may be assigned

on an aldehydic

solutions

OH ~&ES

group

i c oxygen

in

be either

Hz)

resonances

1.46)

to

73.2

species

a proton

similar

The

and

aldehydic

resonance to

(72.0

presence

this A.

methyl-platinum

and phenol

the

assigned

in

non-equivalent

IR.

this

that

The

both

species

is

formulation

containing compound

intensity.

Sal

most is

obtained

both is

however

129

unstable

and

When

loses

a one

Pt(CHS)2(Sal)2 a

new

species

CsDsN

to

form

Pt(CH3),(DH)2nH20

mole ratio of methylamine (isomer 6) in

CDCl3

there

on

standing.

is added to a solution of is

an

immediate

formation

of

two noll-equivalent methyl-platinum groups as

with

evidenced by the presence of two methyl-platinum equal intensity in the NMR

spectrum

(Fig.

resonances of

3a).

The

spectrum

can

be

i i Fig. 3. Pt(CH,)2(Sal)2

(isomer

(b) 2 mol of CHxNHI.

*TMS.

l

I

I 4

I

2

6

interpreted

in terms

of

!

B) plus (a) 1 mol of CHlNH2;

the

I

-r

structure

in Fig.

4A

(R=CH3),

platinum which

resonances are

consistent

Thus

have coupling constants of with

CH3

trajzs

to

an

79.1

aldehydic

the

where

and

iigands

two 67.1

oxygen

methylHZ (cf.,

I

10

8

methylamine has condensed with one of the salicylaldehyde to form an N-methyl salicylaldimine complex.

,

I

I

6

(Table 77.5

11, Hz

130

B Fig. 4. Structures CH,NHz (B)

in

of the reaction

isomer B) and txizs

products

to

of isomer B with one mol of CH,NH?

group

an aldimine

Ph,As[Pt(CH,),Bt-,Sal=N-CHs][l41).

(cf., 67.1

with lq5Pt (Fig. 3a).

together with sate11 ites

The

in

The N-methyl resonance consists of

a central doublet due to coupling between the CH3 proton (3J(HC=NCH3)1.2Hz)

(A) and two mol of

magnitude

of

this

latter

group due

and to

the

imine

coupling

coupling

(8.7 Hz)

is somewhat less than those found in M[Pt(CH3)2Br2Sal=N_CH31 (13.0-13.2 Hz)[14] and [Pt(CHs)sSal=N-CH3L)

(14-16 Hz) [17] indicating

a weaker Pt-N bond in Pt(CH3)2(Sal)(Sal=N-CH3).

This is supported also

by the magnitude of the coupling of the aldimine proton with lg5Pt (22.0 Hz) which

[141.

is less than that in Bu4N[Pt(CH3)zBr2Sal=N-CH3](26.4

Hz)

The aldehydic proton couples with lg5Pt with a magnitude of

15.9 Hz, which is of the same order as that found in isomer B (16.3 Addition of a two mole ratio of methylamine to a CM13 of Pt(CH3)2(Sal)2

Hz).

solution

(isc;nerB) immediately produces Pt(CHS)2Sal(Sal=N-CH3)

as for a one mole ratio.

However, on allowing the solution to stand,

formation of a new species, whose spectrum is shown in Fig. 3b, occurs over a period of about 30 minutes.

The spectrum indicates that the

compound is the bis (N-methylsalicylaldimine) is shcwn in Fig. 46 (R=RI=cH,).

compound whose structure

Thus a single methyl-platinum

resonance is observed with a coupling constant of 68.4 Hz, coupling

of

lg5Pt

proton

(22.5

in

compound

the

Hz)

with are

both of

the

Pt(CH3)zSal

the same

N-methyl order

(Sal=N-CHs).

group as

is

(9.1 found

Hz) for

while

and these

the

aldimine

couplings

131

Although a second mole of CHsNH, reacted quite readily with Pt(CHs)$al(Sal=N-CHs)

as shown above, an attempt to react the latter

species with a-methylbenzylamine

was unsuccessful since no apparent

reaction occurred after heating for 10 hours at 55'C. Reaction of isomer B with a two mole ratio of aniline was extremely slow at room temperature but at 55'C reaction occurred over a period of 3 hours to produce a species whose NMR spectrum was consistent with Pt(CHs)2Sal(Sal=N-CsHS)

(Fig. 4A, R=C6HS).

Thus two non-equivalent

resonances are observed with coupling

methyl-platinum

constants

of

78.7 Hz (tram

to aldehyde group)

Roth aldehydic

6.0 Hz) and aldimine (T 1.83, J 13.6 Hz) (T 0.78, J 1'

protons were observed

and

e 1). (Tab 1'

6815 Hz (trans to aldimine group).

The larger value of 2J(1g5Pt-CH,) t?mls

to N and the smaller value of 3J(1g5Pt-N=CH) compared with the values in Pt(CHs)zSal (Sal=N-CHs) consistent

compound, of

the No

aryl

group

attempt

with

i ndicate a weaker Pt-N bond in the former the

greater

electron

such

a

(Sal=N-CsHs)

reaction. with

was

made

to extend

the

5:

However

CH,NH,

, reaction

reaction

to the

formation

of

extreme

in

view

of

a solution

the

of

of

the

sladness

Pt(CH3)zSal

proceeded at a reasonable rate with the reaction

being complete after 6 hours at 55'C. Pt(CH3)2(Sal=N-C6HS)(Sal=N-CH3) 'H NMR.

properties

[lb].

bis (N-phenylsalicylaldiminato) compound of

- withdrawing

Two methyl-platinum

The product of the reaction was

(Fig. 48, R=CH3;R1=C6HS) according to

resonances are observed with coupling

constants of 70.4 Hz (CHj trans to N-CsHS) and 68.4 Hz (CH3 trarrs to N-CHs) and two aldimine proton resonances at T 1.30, J 19.2 Hz (EC-N-CsHS) and T 2.04, J 22.2 Hz (H_C-N-CHs). Reaction of Pt(CH3)2(Sal)2

(isomer 8) with ethylenediamine

complex than the above reactions and the results more equivocal.

is more Dropwise

addition of en to a CDC13 solution of isomer B produces three new methylplatinum resonances in the lH NMR spectrum.

The intensities of these

7: Species of the type Pt(CHs)2(Sal=N-R)2 would probably be best prepared as has been done with by reaction of Pt(CH 3 2(OH) 2- nH20 with HSal=N-R H acac=N-R ligands [6].

132 resonances indicate that two species, each with two non-equivalent methyl groups are present in so ution in

the

approximate

ratio

of

2:1 with one

resonance from each spec es be ?g accidentally degenerate (Table 1). The magnitudes of the coupling constants indicate that for

each species

one CHS group is trcwzs to an a dehyde oxygen (78.8 and 79.1 Hz respectively) and one trczzs to an aldimine group (66.6 Hz for each). Each species exhibits one aidehyde aldimine (T 1.83 and i possible

structures

resonances

but

it

1.93

which is

(7 0.68 and;

respectively)

would

impossible

give to

0.61 respectively) and one Fig.

resonance. non-equivalent

assign

5 shows

two

methyl-platinum

structures

from

the

NHR spectra.

-NH2

B Fig. 5. Possible products of the reaction of isomer 'B with en.

Further addition of ethylenediamine produces two new species each with equivalent methyl groups truzs to aldimine ligands (Table I).

A

large number of monomeric, dimeric and even polymeric structures could be postulated with equivalent methyl groups so that the species cannot be identified by 'H NMR spectra.

The formation of insoluble material

probably indicates that polymeric species

have

form&d

in the reaction.

Reaction of Pt(CHs)2(Sal),( isomer A) with ethylenediamine immediate precipitation of a white microcrystalline analyses

for

Pt(CHs)2en(OH)2".

solid

results in which

The 'H NMR spectrum of this compound

in D20 exhibits a single methylplatinum constant of 70.7 Hz, consistent wth

resonance with a coupling

CHs group trms

to nitrogen donor

The same species may be prepared by reaction of Pt(CHS)3(0H)3-nH20 with en.

133 atoms

[131.

coordinated From

the

The

infrared

OH at

3591

filtrate

of

(u(OH)),

the

above

coordinated presence even

the

and

acetone.

(phenolic)

[Is],

1 i gands .

On the

appear

be

bonds

trms

this

other

the

reactions

(cSD~N)

formation

of

in

by

remain

the

intact

due

I3 the

and

such

in

the

and to

their

high

tzw:s

the

salicylaldehyde

groups the

involved

in

either

-

The

do not

Pt-0

suggests

formation

the

tend

of

(amines)

the

A)

groups

only

systems

by IR spectra.

OH groups

phenolic is

it are

during

of bis-

(isomer

to

that

of

to

(w(Pt-0))

ethylenediamine

methyl

due

cm-l

confirmed

by

CSDSN,

reactions

in

species

as

displacement

which

condensation

hydroxo

as

558

crystals

displaced

isomer

groups

and

peaks

Pt(CH3)2(Sal)2

positions

OH groups

methyl

in

complete

in

contains

(6(OH))

yellow

Since

trcrrzs

hand,

or

bonds

in

results

displaced to

(phenolic)

such

ethanol Pt-0

969

that

readily

ligands

compound

be obtained

are

of

influence

to

groups

and

can

indicate

a variety

aqueous

weaken

reactions

the

reaction,

imine

aldehyde of

989

above

(salicylaldehyde)cethylenedi The

of

spectrum

the

(aldehydic)

displacement lack

of

the

Pt-0

Schiff

base

complexes. Experimental Analytical

,

Z%epaz-atioiz

results of

for

Ptr (Cfiq)

9 (Sa ZI 7

Pt(CH,),(OH),*nH,O

and

the

several

heated

minutes

heating

was

required

evaporated

orange-yellow

solution to

plates

sample

solutions

the

sol

id

1ization. off,

compound

appears

remaining the

on

solid

addition

of

water

to The

washed to

unchanged

compound

in

The

was

are

bath

product,

after treated

Table

2.

sal icylaldehyde

the

with

solution The

the

and n-hexane form

and

of

air

indefinitely 4 months.

was

air.

chloroform,

volume

z-hexane

ml)

of

When

95% ethanol

added

orange-yellow

dried. in

ml)

after

orange

a stream in

in

(0.5

resultant

in

(5

dissolved

ethanol

The

a small

stable

in

usually

dissolved

with

be

listed

/.I

dissolution.

concentrated

filtered

of

1ine

are

suspended

boi ling.

ready

dryness

crystal

crystal

was The

one

to

was

although

for

fi ltered,

induce

to

compounds

(isonisr

(0.69)

mixture

sometrmes

the

the

Yield solid

chloroform or

aqueous

952.

state,

_

134 TABLE

ANALYTICAL

2

DATA

Empirica? formula

Compound

Analysis

(calcd, (found)) (%) H

C C1sHxeOri”t

B

Cl6H16gL;Pt

Pt(CHs),fSa!)(Sal=N-CH3)

Cl7HlsNu3Pt

ClaH2zN20zPt

PtfCH3)2(Sal=N-CsHs) (Sal=N-CH3)

Czd%.$WW’~

C4H16N202Pr

41.1

3.5

(41.2)

(3.5)

41.1

3.5

(41.2)

(3.51

N

4.0

2.9

(42.3)

(4-O)

(3-o)

43.8

4.5

5.7

(43.9)

(k-61

(5.6)

49.7

4.4

5-o

(49.7)

(4.5)

(5.0)

15.0

5.;

8.8

(14.8)

(5.51

(8.4)

42.5

acetane the solution becomes cloudy and the odour of salicylaldehyde becomes noticeable,

Evaporation of the solution and extraction with

chloroform leaves a pale yellow residue which has an identical infrared spectrum to that of Pt(CHs)2(0H)2*nHz0.

Pt(CH3)g(Sal)2

(isomer A) (0.5s) was dissolved in m-dichlorobenzene

(8 ml) and the solution heated to boiling.

Metallic platinum began to

precipitate from solution after 30 seconds but heating was continued for 8 minutes at which time the IiiNMR spectrum confirmed that only a single species was present in solution,. The solvent was then evaporated by heating on a water bath in a stream of air.

The residue was

extracted with chloroform, charcoal added to adsorb the colloidal platinum, and

135 the

solution

and

the

yellow

remove

all

stable

indefinitely

of

Several

both

of

NMR spectra

boiling.

Initial

amount

of

occurred

difficult

as

intractable

was

with

C.

Both

than

30-402,

increased

at

rise

to

no evidence

amount

the

expense it

On the

reaction.

dicyclopentadiene group to

which

platinum

in

Pt(CH3)2(Sal)z

of

the

of

z-hexane. to

appears

solutions

to

be

of

about

only

slower,

same

was

no

of

the

as

total

in

the reaction for

product

A similar

this

case

much

2 hours

evidence

the

formed. in

after

complete

isolation be

was

but

the

there

isomer

at

C was

the

expense

never

In

was result

there

was

at

shaded

to

of

dicyclopentadiene

an extent

greater

of

isomer 1 ing

isomer

C did

There

presence

A in of

in

was the

both

a free

may be

B

solvent,

throughout

isomer

isomers

al though

lower-boi

stage

species,

reaction,

present.

any

the

new

while

amount

species

tetrachloroethylene

h.!o

the

the

the

NMR spectra

the

of

constant

A.

total

both

present

fairly

that

the

in

A.

throughout

isomer

pyridine

(isomer

was

to

present

hand

reaction

the

Pt(CHs)2py2(OH)2.

appeared

Former

also

although

that

of

that

was

for

investigated

conversion

and

salicylaldehyde

other

were

dicyciopentadiene,

remaining

50% of

and suggests

in

tended

isomer

free

and

Hc+iever,

were

the

for

state

solutions

isomers

almost

solid

heating

decreased

tetrachloroethylene, fact

of

indicated

in m-dichlorobenzene

compound

complete

tars

and m-dichlorobenzene H and

The

With

formation

IH NMR spectra

i vo1um

necessary

tetrachloroethylene,

metal.

pyridine

substantial

sometimes

80%.

eventual?y

5 minutes

platinum

a smal

addition

Yield

formation

formed

of

to

by

is

solvents

With

B.

formation

also

boiling

reaction.

within

found

the

platinum

m-dichlorobenzene

precipitated charcoal

indicating

platinum

concentrated

acetone.

high

isomer

slcwer,

in

and

other

preparation

with

platinum.

ethanol

was

product

ization

traces

chloroform,

filtrate

crystalline

recrystall

A second

The

fi Itered.

aldehyde

coordinated

solution.

A)

(0.049)

was

dissolved

in

CDC13

(0.5

ml)

136 in the

an NMR tube. reaction 50:50

a stream

of

The

The

confirmed

Zeaction

to

as

during

spectra

which

an NMR tube.

lH

NHR spectra

extracted

6)

time

it

of

and

(isomer A solution

then

the

6)

(0.049)

of

CH3NH2 in

complete to

added.

product

more

amount

separated.

the

free

of

Pt(CH3)2Sal

than

methy!

after to

(isomer A solution

required

of

‘separated.

leaving

in a

spectrum. by

‘H NMR.

was

CDCls,

was

allcwed

to

to

deep

red

products

in

solution.

in

CDC13

treated stand

and

lH

for NMR

of

the

added

were

to

f i 1 tered

ml) until

The

product. to

solution

(0.5

dropwise

desired

concentrated the

2 moles

8)

(0.049)

of

CH3NH2 in

of

being

CHsNH2 per

estimated

resonance

was

of

by

a small

stand, off

NMR spectra

30 minutes

at

room

a beaker, the were

filtered

mole

of

to off

in

yellow

and

the

of

a small

stand

yellaEI air-dried.

dropwise were

the

the The

to

(0.5

until added,

resonances

formation

solution

was

volume

and

prisms

of

Yield

ml)

intensities

methyl-platinum

indicated

and

CDClS

platinum

comparison

temperature.

concentrated solution

dissolved

CDC13 was added

CH3NH2 and

_

These

CDCIS was

These

(Sal=N-CH3)

On allowing

dissolved

30%.

Pt(CHS)2(Sal)2 an NMR tube.

was

On allowing

of Pt(C~qJ3(Sa~=I?T--CA?I)7

added.

dryness

infrared

in

yellow

a beaker,

_Prepa.ration

transferred

to

complete

CsDgT

formation

Yield

product

and

was

confirmed

solution from

ai r-dried.

the

as

decomposition

transferred

n-hexane

of

slightly

its

dissolved

final

changed

reaction

chloroform

nH20 by

B) with

solution

evaporated

with

(O.Obg),

The

A.

indicated

was

crystals

in

was

the

of Pt(CH11~SaZ(SaZ=??T-C~91

in

volume

was

Cisomer

a number

Pt(CH3)2(Sal)2

solution

solution

to

When

Pt(CH3)2Sal(CSDsN)OH

isomer

indicated

P~epaxctioz

the

(isomer

for

dropwise

Pt(CH3)2(OH),-

of Pt(CH~)plSaZl~

CsEsN

3 days

be

added

NMR spectra.

lH

solid

contained

Pt(CHs)2(Sal)2 with

by

CDC13:CSDSN)

air.

solution

was

CgDgN

monitored

(approx.

residue

Neat

of

the

then

n-hexane the

95%.

product

137 Reaction

of P~(CHJ)~(S~Z)~ (isomr B) ~6th aniZi=e

Pt(CHs)2(Sa1)2 in

an

NMR

tube

The

solution

as

confirmed

9

hours

with

and

by

B)

a solution

initially NMR

of

Attempts

to

but

species

intractable

isolate

gums

in

The

to

the

form

on

added

solution

pure

evaporation

dropwise.

during

were

of

for

55’C

consistent

reddish

form

ml)

aniline

at was

became

in

(0.5

unreacted

spectrum

solution

CDC13

(1:lO)

and

NMR

product

in

CDC13

heating

whose

this

tended

line

dissolved

Pt(CH3)2(Sa1)2

(Sal=N-CSHS) .

Pt(CH3)zSal

ani

spectra,

a single

was

(O-039)

contained

lH

produced

time. as

(isomer

this

unsuccessful

the

solution.

Preparation of Pt(CH?l~/SaZ=N-CF;351ISaZ=il-CH~) To

a solution

des cr i bed one

mole

of

CH3NH2 of

hours

of

at

the

The

added,

filtration

and

z-hexane

and

were

and

the added.

fi

ltered

was

methyl

the

added

by

was

ai r-dried.

to

with

crystals

Yield

relative

complete

a beaker,

to of

After

formation

activated

concentrated

yel1o.d

until

resonances.

transferred

heated

as

dropwise

indicated

indicated

then

On standing,

prepared

methyl-platinum

was

solution

was

as

spectra

solution

and

CDC13

present

solution

yellow

off

in

and

NMR

reddish

(Sal=N-CGH3)

CH3NH2

platinum

temperature,

product.

After

per

of

methylamine

room

chloroform

Pt(CH,),Sal

a solution

above,

intensities 6

containing

the

charcoal.

a small

volume

product

formed

90%.

Reaction of Pt(Cli~~7lSaZl7(ison;er31 witi? ethyZenedim%ze Pt(CH3)2(Sal)2 an

NMR

After

tube the

and NMR

a solution

spectrum

ethylenediamine for

2

hours

was

then

which

filtered

to

filtrate

concentrated

a ye1 low

solid.

was

of of

solution at

a mixture

was

time

of

compounds

(0.039)

dissolved in

intermediates added

data

and

had the

for

to

amount

volume this

in

CDC13 been

soluticn

appeared

a small

a small

Analytical

was

ethyienediamine

reaction

remove to

(0.05g)

the

Reaction of Pt/CH~)~(SaZl~ Pt(CH3)2(Sal)z

B)

(isomer

of

and

be

added

(0.5

excess to

complete.

precipitated added

indicated

ml)

dropwise.

recorded, allowed

z-hexane

solid

CDC13

stand

The

solution

sol

Id,

to

precipitate

that

the

there

present.

(isomer Ai with etir.qZenedianine was

dissolved

in

chloroform

(2

ml)

and

a

in

solution

of

immediate This

ethylenadiamine

formation

was

of

filtered

volume

and

crystal

line

r.-hexane

The

id.

to

obtained

by

concentration

yield.

lock

considered

analysed the

and

initial

were

addition

(TMS)

recorded

using

accurate

to

sweep

Pt(CHs)zen(OH)z

as

270

and

coupling

IR

PS-100

Hz.

small

and

was

solid

This

its

a

a white

a yellow

?z-hexane.

width

+-O.Olppm

to

for

JEOL

activated

concentrated

by

a

with

product

of

on

treated

filtrate

was

precipitate.

the

ethylenediimine

NMR spectra

internal

and was

There

dropwise. 1 ine

ethanol

solution

product

bis-(salicylaldehyde) ‘H

in

precipitate

From

70%

added

microcrystal

the

added

in

be

off-white

filtration,

sol

chloroform

dissolved

obtained

to

an

off,

After

charcoal.

in

was

was confirmed

spectrum-

spectrometer

Chemical

on

shifts

constants

to

are

20.5

Hz.

References

1.

R.C.

Menzies,

2.

A.K.

Chatterjee,

J.

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Henzies,

J.R.

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Chem. R.C.

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J.

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