Synthesis of Oxorhenium(V) Complexes of Heterocyclic-N,O and -N,S Ligands

The complex trans-ReOCl 3 (PPh 3 ) 2 reacts with potentially bidentate N,O- and N,S-donor benzimidazolylalcohols and benzimidazolylthiols (HL) in ethanol to produce the compounds ReOGl 2 (L)(PPh 3 ) or ReOCl(OEt)(L)(PPh 3 ), depending on the reaction conditions. The complexes were characterized by elemental analysis, NMR, vibrational and optical spectroscopy. Mechanisms for the formation reactions and probable configurations of the products are proposed, and these are supported by qualitative studies and spectroscopy.