Iron-molybdenum-sulphur and iron-tungsten-sulphur complexes of diimines

Abstract

The complexes FeLMS 4 (L = bipy or phen; M = Mo or W) were prepared and characterized. The linearity of the χ −1` M vs T plot and Mössbauer spectral parameters (δ: 0.28 mm s −1; E Q: 0.37 mm −1) of [Fe(bipy) 2MoS 4] suggested that iron(II) assumes a distorted octahedral geometry with an intermediate spin state. The thiometallate acts as a bidentate chelating ligand towards iron(III), as evidenced by IR spectral results. An irreversible anodic wave observed at +1.04 V vs S.C.E. in the cyclic voltammogram of [Fe(bipy) 2MoS 4] in DMSO suggested the oxidation of iron(II) to iron(III) and the reduction of the bipyridyl ligand occurs at −1.40 V.