Two unusual ions, [Cu(C7H7)]+ and [CuL[C7H7)]+ in the mass spectrum of a copper(II) β-diketoenolate

INORG. NUCL. CHEM. LETTERS

TwO .n(:sl:aL 1 0 n s

Vol. 8,

pp. 119-122, 1972.

+

[cu(cTHT)]

Pergamon

Press.

Printed in Great, Britain.

LcuzJLc~x7)I+ IN TIlE ~ S S

and

SPECTRUM OF A

COPPER ( l I ) [3 -D I KETOENOI~&TE ,J.A.

Kemlo a n d T.M. S h e p h e r d D e p a r t m e n t of C h e m i s t r y The l ~ u r d i e B u i l d i n g The U n i v e r s i t y St. Andrews

i R e c e i v e d 21 October 197D

As p a r t

of a general

study

2,4-pentanedionato)copper(II) Cu(Ctt3COCHRCOCII3) 2 ( F i g . by a p r e v i o u s l y %H

f.

6.6,

c.

source

temperature,

469,471

(2.0,1.0)~I

(~1-112) +, 204

(d)

(I.6)-(LH)*,

(CuL-I12)* with as

and

fragment The

ions

in t h e

one or

both

gi vc t h e

indicates

of

the

(3),

benzyl

pattern

is

linkage,

66.5,

c.

of

66~4,

a MS902 s p e c t r o m e t e r The m a j o r +,

266,268 +,

~

markedly

(o)

ions a are 357,359

(a)

(9.5,4.5)-

(73.5,34.3)-(CuL)

(h)

154,156

The i o n s

feature

different

being

C-CH2-CII2-Ph.

gr-,ups giving

ions

particularly

abundant

(Relative

f.

of

may b e s a t i s f a c t o r i l y

ion Cut + also ion g.

+,

(f)

(5.5,2.5)-

lower mass, accounted

- ion

species

119

from that ready

for

dipositlve

readily

of copper

cleavage

The m o l e c u l a r

Evidence

w h i c h may b e r e p r e s e n t e d ,

Intensity)

the

b__ a n d d ( t i l e

a m/e

mass spectrum

l igand.

the dominant

ion

(e)

(6.4,2.9)-(CuL-133)

monoligand

this

using

(41.4,19.1)-(M-91) +,

the

The c o m p l e x w a s p r e t ~ r e d

(1OO.0,45.5)-(Cul-91)

the

that

and

we h a v e e x a m i n e d

< 10 -5 nun.

t h e Cu + i s o t o p e s ,

dimethylene

been observed) to

I75,177

of bis(3-substituted

(Analysis:-%C

(]0.0,4.5)-(M-182)

fragmentation

acetvlacetonate bond

378,380

of

mass spectra

were obtained

, (b)

133,135

the exception

(2).

- pressure

(K) (i)

method

200°C

287,289

the

1) w h e r e R = - ( C H 2 ) 2 P h .

Spectra

+

of

complexes

described 6.4).

(1)

loses

from other

ion,

of

t h e ('-<2

M+,

loses

ion d has a benzyl

also group

complexes

(1)

120

MASS SPECTRI;M OF A COPPER(II) !3-DIKETOENOLATE

/CH 3

,/o Cu

Vol. 8, No. 2

+

, C--CH 2

\ o .... is p a r t i c u l a r l y

stable.

In a d d i t i o n

to loss of benzyl,

(C}{3COC(CH2)COC}]3) o c c u r s Accurate

reaction

c. 357.0916)

path,

[Cu(C~{7)] + seems

from both M + and Cul,+ g i v i n g

mass m e a s u r e m e n t s

(f. 357.0918,

M+

loss of the c o m p l e m e n t a r y

confirm and

these

]53.984[,

~ ( M - I ] 2 ) + has been e s t a b l i s h e d

has not been

found although,

fragment

ions c__ and 11.

ions as c o r r e s p o n d i n g

[Cu(C~{7)] + (f.

ligand

c.

(Fig.

by analogy,

to

[CuL(C~{7)] +

]53.9844).

2).

derivation

The

The origin of from CuL +

probable. Considering

compounds

the r e l a t i v e

the a b u n d a n c e

instability

of these

FIG.

I.

of most

ezopper o r g a n o m e t a l lic

ions

is u n e x p e c t e d .

Mass

spectrum

of

The

intramolecular

CuI, 2.

I

'1

I d

i!

f

'

• 1 ,,,~,

l.l,i

m

L

,

I~

e

k

2~ ale

j

h

Vol. 8, No. 2

+ M

MASS SPECTRUM OF A COPPER (11) ~ - D I K E T O E N O L A T E

-91

+ ,~ ( M - 9 ] )

(a)

-91

,= ( M - I 8 2 )

(b)

(M_112)+

-91

+

(d)

,~ (Cui 5~

I (CuL-91)*

-91

(e)

(c)

121

(g)

L~

-42

(Cu. - 1 3 3 ) +

(h) I'~G,

2.

Reaction

nature of the bonding

ion reaction

interaction

mo[~.~cular i o n dimethylene phenyl to

group

give

occurs

between

to cleavage

linkag(.'.

Since

is unlikel.y

a tropyIium (4).

and

copper

giving

the

of the

from presence

This interaction

suitable

suggests R, and

metal-oxygen

bond(s)

bondi.ng between

that

type

of metastable

substituent,

s±gni, f i c a n t

we s u g g e s t

ring.

Bonding

established

leading to [CuL(CT/[ 7)

prior

PhCIt2CN the

paths

a benzyl,

may t h e n

'template'

occur

the

COlUm'r ±n the,

and the

the

has

copper

been

between

conditions

that some form of

and

the

+ i n M may r e a r r a n g e

group

of arrangement

ions.

for

report~.d

this

the

ring

for

syst~m

production

of

ion c. We h a v e a l s o w h e r e R'

=

potential

between

occurs

el" CuI.2,

[Cu(C7117)-

in

leaving

the copper

spectrum

the

-Ctt2Ph a n d CuL2,

. rcu(CTn 7) ]+ the

examined

(1.1)

and

the

spectrum

fragment the

of

the

w h e r e R" = - ( C I I 2 ) 3 P h .

is

o f Cul. 2. much l o w e r

substttuent

in contrast, and,

mass spectra

In this than

the

ions

complexes

Neither case,

that

the

stability

hindered.

relative

t o CH3CO

:

and

method used

for

The

[Cu(C8tlg)J + (4.0)

IOO.

T h e ' s e c o m p t e x e s w o r e p r e p a r e d by t h e s,~ti, s f a c t o r y analytt~;a~l t'igures.

of

(0.1),

+ abundance

i

, CuL2,

[Cu1.'(C71t7)] + n o r

[CuL"(CTIIT)] +

[Cu(C8H8)] + (6.0)

b

i n Cul 2 a n d i n t e r a c t i o n

may b e s t e r i c a I l y

contains

in add±tion,

related

Cul. 2 a n d gave.

-

122

MASS SPECTRUM OF A C O P P E R (11) {3-DIKETOENOLATE

Voi. 8, No. 2

REFERENCES

(I)

J.A. KEMLO and T.M. SIIEII{ERD, unpublished work.

(2)

T . M . SHEPHERD, Chem. and I n d . , 5 6 7 , (1970).

(3)

C . G . ~CDONALD and J . S . SHANNON, A u s t r a l . J. Chem., 19, 1545, (1966).

(4)

N.M.M. NIBBERING and Th. J. DE BOER, Tetrahedron L e t t e r s , 24, 1435, (1968).