A VANADIUM-CONTAINING IRON-SULFUR CLUSTER WITH A V2FE2S4 CUBANE-LIKE CORE - SYNTHESIS, STRUCTURE, AND CHARACTERIZATION OF (ET(4)N)[V2FES4(ME(2)DTC)(5)]

A cubane-type cluster (Et(4)N)[V2Fe2S4(Me(2)dtc)(5)] (1) has been synt hesized from an assembly system VS43-/FeCl2/Me(2)dtc(-)/PhS(-) in acet onitrile (Me(2)dtc(-) = dimethyldithiocarbamate). The compound 1 . 2CH (3)CN crystallizes in the monoclinic space group P2(1)/c (No. 14), wit h a = 12.174(3) Angstrom, b = 22.135(4) Angstrom, c = 19.712(5) Angstr om, beta = 105.43(2)degrees, V = 5120.3 Angstrom(3), rho(cald) = 1.50 g/cm(3), and Z = 4. The structure was solved from 6336 unique reflecti ons (I > 3 sigma(I)) and refined by a full-matrix least-squares method to R = 0.053. The cluster anion contains a cubane-like [V2Fe2S4](4+) core, in which the V-V, Fe-Fe, and V-Fe(mean) distances of the V2Fe2 t etrahedran are 2.745(2), 2.681(1), and 2.780(6) Angstrom, respectively . The Mossbauer effect and the structural parameters indicate that the oxidation states of the Fe and V atoms in the [V2Fe2S4](4+) core are both +3. The H-1 NMR shows the paramagnetism of the cluster. The chemi cal shift of V-51 NMR was observed at -391 ppm. The FAB-MS behavior of the cluster indicates the bond breaking of the cluster core.