New Group 6 metal carbonyl derivatives of 2-(2′(-pyridyl)benzimidazole: synthesis and spectroscopic studies

Abstract

Reaction of Cr(CO) 6 with 2-(2′-pyridyl)benzimidazole (pbiH) under reduced pressure resulted in the formation of the dinuclear complex [Cr 2(CO) 6(pbiH) 2]. Infra-red (IR) spectroscopy revealed the presence of terminal and bridge CrCO bonds. Interaction of M(CO) 6, MCr, Mo and W, with pbiH in the presence of 2,2′-bipyridine (bpy) gave the tetracarbonyl complexes [M(CO) 4(pbiH)]·bpy. Spectroscopic studies of the complexes indicated the presence of hydrogen bonding between the bpy nitrogen and the NH group of pbiH. Reactions of M(CO) 6 with pbiH in the presence of PPh 3 gave the tricarbonyl monosubstituted derivatives [M(CO) 3(PPh 3)(pbiH)]. The spectroscopic studies of the complexes suggested the proposed structures.