Synthesis, characterization of novel half-sandwich iridium and rhodium complexes containing pyridine-based organochalcogen ligands

A series of neutral pyridine-based organochalcogen ligands, 2,6-bis(1-methylimidazole-2-thione)pyridine (Bmtp), 2,6-bis(1-isopropylimidazole-2-thione)pyridine (Bptp), and 2,6-bis(1-tert-butylimidazole-2-thione)pyridine (Bbtp) have been synthesized and characterized. Reactions of [Cp∗M(μ-Cl)Cl]2 (Cp∗ = η5-pentamethylcyclopentadienyl, M = Ir, Rh) with three pyridine-based organochalcogen ligands result in the formation of the complexes Cp∗M(L)Cl2 (M = Ir, L = Bmtp, 1a·Cl2; M = Rh, L = Bmtp, 1b·Cl2; M = Ir, L = Bptp, 2a·Cl2; M = Rh, L = Bptp, 2b·Cl2; M = Ir, L = Bbtp, 3a·Cl2; M = Rh, L = Bbtp, 3b·Cl2), respectively. All compounds have been characterized by elemental analysis, NMR and IR spectra. The molecular structures of Bbtp, 1a·Cl2, 1b·Cl2, 2b·Cl2 and 3b·Cl2 have been determined by X-ray crystallography.