Mixed metal pentanuclear clusters [MFe4S4(CO)12]z− (M=V, Mn and Cr; z=0, 2) and X-ray crystal structures of [VFe4S4(CO)12] and [MnFe4S4(CO)12]2−

Reaction of VCL3, MnCl2 and CrCl3+Zn with [Fe2S2(CO)6]2−, from reduction of [Fe2S2(CO)6] by LiEt3BH, resulting in pentanuclear mixed metal clusters [VFe4S4(CO)12] (1), [Et4N]2[MnFe4S4(CO)12] (2) and [Et4N]2[CrFe4S4(CO)12] (3), respectively. Complexes 1, 2 and 3 have been characterized by elemental analysis, spectroscopy and the crystal structures of 1 and 2 have been determined by X-ray crystallography. The structures of 1 and 2 contain a penta-nuclear M–Fe–S core, [Fe2S2MS2Fe2]z− (M=V, z=0 (1) and M=Mn, z=2 (2)), consisting of two [Fe2S2]-units chelating to a metal atom. The two [Fe2S2] units are in ‘butterfly’ type configuration like the one in [Fe2S2(CO)6]2−. In 1 there are four V–Fe bonds of 2.822–2.865 Å, but in 2 there were no Mn–Fe bonds found. V–S distances are 2.205–2.210 Å and Mn–S bond lengths are 2.358–2.380 Å. The novel structural configuration, IR spectra and synthesis were discussed.