Oxo-carboxylato-molybdenum(vi) complexes possessing dithiolene ligands related to the active site of type II DMSOR family molybdoenzymes

Abstract

Spectroscopic and kinetic studies indicate that oxo-carboxylato-molybdenum(VI) bis-dithiolene complexes, (Mo^VIO(p-X-OBz)L₂), have been generated at low temperature as active site structural models for the type II class of pyranopterin molybdenum DMSOR family enzymes. A DFT analysis of low energy charge transfer bands shows that these complexes possess a Mo–S_dithiolene π-bonding interaction between the Mo(d_xy) redox active molecular orbital and a cis S(p_z) donor orbital located on one of the dithiolene ligands.