A tetrahedral complex of cobalt(II) and nickel(II)

INORG. NUCL. CHEM. LETTERS

Vol. 10, pp. 365-366, 1974. Pergamon Press.

Printed in Great Britain.

A TETRAHEDRAL COMPLEX OF COBALT(II) AND NICKEL(II) A.W.Downs, B.A. GStz and A.E.McOarthy Department of Chemistry, University of Aston in Birmingham, Gosta Green, Birmingham B4-7ET (Received 18 December 1973) S~mary

The compound d e s c r i b e d morphous replacement

is a tetrahedral by cobalt(If)

complex of nickel(If)

occurs.

Nitrogen

in which iso-

is the donor atom in

this compound. Experimental and Discussion It has been previously reported (I & 2) that the sole product of reaction of 2-methylpyridine with nickel(II) thiocyanate was red, diamagnetic, dithiocyanato-bis 2-methylpyridinenickel(II).

Re-examination of the system

using an aqueous solution of nickel(II)thiocyanate

gives several unrecorded

products. The most interesting of these consists of short dark-blue crystals produced in only very small quantities. The dark-blue crystals are composed of dithiocyanato bis 2-methylpyridinenickel(II)/cobalt(II) in which the metal ion is tetrahedrally coordinatedby nitrogen only.

Some crystals of the dark-blue compound

showed marked X-ray fluorescence on exposure to CuE

radiation while others

showed hardly any. None of the crystals showed X-ray fluorescence when exposed to Cr K

radiation indicating that some of the crystals contained

both cobalt and nickel.

This was verified using conventional qualitative

inorganic analytical tests.

Quantitative analysis showed that the nickel

content varied between 3.5 and 9.0%0. The total metal ion content was 16.3%.

365

366

TETRAHEDRAL COMPLEX

Vol. 10, No. 5

A l l t h e c r y s t a l s examined, v a r y i n g from t h e n i c k e l f r e e

compound,

through

to t h o s e c o n t a i n i n g 9.0~ of n i c k e l were isomorphous. The c r y s t a l d a t a was c o n s i s t e n t w i t h an orthorhombic u n i t

cell with a = 12,96 ~ , b = 14,60 ~ , c = 8,69 ~ density D M was approximately 1,41 g c m -3.

and

= 1644 ~ 3.

D C = 1,46 g e m -3, X = 4.

The Equi -

inclination Weissenberg photographs were taken about the three principal axes and the reflections indexed when it was found that hO0 is present only when h = 2n , OkO is present only when k = 2n, indicating that the space group is P21212. The infra-red spectrum of the nickel-cobalt complex shows strong CN stretching frequencies at 2070, 2090 and 2118 cm-l;

the complex containing

-i cobalt only shows bands at 2068 and 2090 cm .

Analytical M i c r o - a n a l y s i s gave C = 46.7%, H = 4.0~o, N = 15.5~, S = 17.65~. C a l c u l a t e d f o r C14H14CO(l_x)NixN4S2;

C = 46.6N, H = 3.9~o, N = 15.5%,

S = 17.7N t o t a l m e t a l 16.3~. A n a l y s i s f o r n i c k e l gave 3.5 t o 9.0~, depending on t h e sample f i g u r e s f o r c o b a l t gave a b a l a n c e t o 16.3~ t o t a l m e t a l . There was no s u l p h a t e i n t h e compound.

References 1.

h.V. Logan and D.W. C a r l e , J. Amer.Chem. S o c . , 7 4 , 5244 (1952)

2.

H.O.A. King, E. K6r~s, S.H. Nelson, J . C h e m . S o c . , 544 (1963). Acknowledgement The a u t h o r s wish t o t h a n k Mr. S. Ludlow f o r e x p e r i m e n t a l a s s i s t a n c e .