SYNTHESIS AND PROPERTIES OF [M6X12(C3H7NO)(6)]X-2 (M=NB, TA X=CL, BR)

Reactions of the complexes [M6X12(C2H5OH)(6)]X-2 (M = Nb, Ta; X = Cl, Br) with N,N-dimethylformamide afforded a new series of clusters of th e composition [M6X12(C3H7NO)(6)]X-2. These microcrystalline substances are not isotypic with any other series of niobium and tantalum cluste rs with the [M6X12](2+) unit. The analytical and spectral data point t o the conclusion that all octahedral coordination sites in the hexanuc lear cluster units are occupied by the oxygen bonded N,N-dimethylforma mide molecules. (C) 1998 Elsevier Science S.A.