Reactivity of tetrathiometalates with alkynes. Synthesis and characterisation of dithiolene complexes of Mo, W, and V by ESMS and XRD

The reaction of DMA (C2(CO2Me)2) with MoS 4 2− , WS 4 2− , and VS 4 3− led to six dithiolene compounds. (NEt4)2[Mo2(X)2(μ-S) 2(η2-S2C2(CO2Me)2)2] 1, (X = O or S), (NEt4)2[V(η2-S2C2(CO2Me)2)3] 2a, (NEt4)2[V(O)(η2-S2C2(CO2Me)2)2] 2b, (NEt4)2[W2(S)2(μ-S)2(η2-S2C2(CO2Me)2)2] 3, (NEt4)2[W(O)(η2-S2C2(CO2Me)2)2] 4 and (NEt4)2[W2(μ-S)2(η2 -S2C2(CO2Me)2)4] 5 were isolated in the solid state. The structures of 2a, 3, 4 and 5 were determined by single crystal X-ray diffraction study. The compounds 1 and 2b were characterised in solution by ESMS (Electrospray Mass Spectrometry) and in the solid state by IR spectroscopy. ESMS data also allowed proposal of a reaction scheme which rationalizes the formation of the different species present in solution.