SYNTHESES AND CRYSTAL-STRUCTURES OF HEPTANUCLEAR CLUSTERS [VS4(CUPPH(3))(5)BR(2)CUX] AND [VS4(CUPPH(3))(5)BR(2)CUX]CENTER-DOT-CH2CL2 (X=0.5BR+0.5CL)

The preparation of the title compounds of heptanuclear heterometallic clusters by heating a mixture of (NH4)VS4, CuCl, PPh(3) and Et(4)NBr i n a solid state reaction at low temperature has been investigated. The compounds [VS4(CuPPh(3))(5)Br(2)CuX] (1) and [VS4(CuPPh(3))(5)Br(2)Cu X]. CH2Cl2 (2) have been characterized by single-crystal X-ray diffrac tion. The clusters consist of a tetrahedral VS4 core bound to an octah edral array of six copper atoms which have two different coordinations , trigonal planar and tetrahedral. Each copper atom is bound to a term inal ligand: five of these are PPh(3) molecules and one a halogen atom . The geometries of the two additional bridging bromine atoms are diff erent in the title clusters. For cluster 1 both bromine atoms are mu(2 ) atoms, while for duster 2 one is mu(2)-Br and the other mu(3)-Br.