Spectroscopic investigation on the molecular and electronic structure of [Mo3S13]2−, a discrete binary transition metal sulfur cluster

The only known discrete transition metal sulfur cluster [Mo3S13]2− has been investigated spectroscopically (XPS, UV/VIS, IR and Raman) and by a cyclovoltammetric study. It turns out that the cluster consists of three Mo atoms with the oxidation state +IV and six S2−2 ligands. A simplified MO treatment of the metal system in [Mo3S13]2− explains the diamagnetism of the compound, as well as the single bond character of the MoMo bonds. The two absorption bands in the visible region are due to a transition within the Mo3 metal system and the charge transfer transitions π*v(S2−2) → d(Mo).