SYNTHESIS OF 2 NOVEL POLYMERIC HETERONUCLEAR CLUSTER COMPOUNDS, [MOS4CU6X4(PY)4]N (X=BR, I) - CRYSTAL-STRUCTURE OF [MOS4CU6BR4 (PY)4]N

The title compounds [MoS4CU6X4(PY)4]n (1:X = Br; 2: X = I) were obtained by the reaction of [NH4]2 [MoS4], CuX and [Bu4nN]X (X = Br, I) in the solid state and pyridine substitution of the solid state product in acetonitrile. Dark crystals of 1 are tetragonal, space group I42dBAR with unit cell parameters a = 14.611 (3), c = 15.119 (13) angstrom; V = 3227.1 angstrom3; Z = 4, D(calc) = 2.55 g cm-3, R = 0.030 for 586 observed reflections. The X-ray analysis confirms that the structure, which possesses a crystallographic 4BAR symmetry axis situated at the Mo atom, consists of a tetrahedral MoS4 core enveloped by an octahedral array of six copper atoms, forming an MoS4CU6 aggregate. Linked by -Cu(eq)-Br-Cu(eq)- bridges, this aggregate connects with its nearest, neighbours and develops a two-dimentional network. The Mo-Cu lengths range from 2.645(1) to 2.668(l) angstrom.