Trinuclear vanadium dialkyldithiocarbamate complexes. Synthesis, structureand spectroscopic characterization of [Et4N][V-3(mu(3)-S)(eta(2)-mu-S-2)(3)(Et(2)dtc)(3)]center dot 2CH(3)CN

A series of [V3S7(R(2)dtc)(3)](-) complexes (R = Et (1), HOCH2CH2 (2)) have been studied by X-ray diffraction, IR, NMR and cyclic voltammetry. The V3S 7 complexes show almost the same core structure features as those of corres ponding [Mo3S7(R(2)dtc)(3)](+) complexes. Three V atoms possess very simila r structure parameters implying their equivalence and electronic delocaliza tion in the V3S7 core. The H-1 NMR signals of the ligating R(2)dtc ligands for the V3S7 complexes occur in pairs. The signals of alpha-CH2 for complex 1 were found at 7.64 and 7.66 ppm and at 7.01 and 8.00 ppm for complex 2, which significantly shifted downfield when compared to those of the respect ive R(2)dtcNa. This can be explained by the contact effect of the paramagne tic center through the S2C=NCH2 group. The cyclic voltammogram displays two reversible couples at - 1.14 and 0.00 V responsible for 1 - /2 - and 0/1 - redox processes, respectively, of the V3S7 complexes. (C) 1999 Elsevier Sc ience S.A. All rights reserved.