SYNTHESIS AND REACTIVITY STUDIES OF METAL CARBONYL COMPLEXES WITH PYRIDINE/THIONE MIXED-DONOR LIGANDS

A new synthetic route to o (mercaptoimidazolyl)pyridine ligands (R = Me, Bun) through a neutral intermediate o (imidazolyl)pyridine (o-impy) has been developed. The n-butyl-substituted ligand shows improved solubility in organic solvents. The alkyl substituent used does not have a major effect on the amount of electron donation to and from the metal center. The addition of a methylene spacer between pyridine and the imidazole increases the N-M-S bite angle for metal complexes. The coordination chemistry of o (mercaptoimidazolyl)picolines o mpicR (R = Me, Bun) to prepare LMo(CO)4 and LM(CO)3X (M = Mn, X = Br; M = Re, X = Cl, Br) was explored. The group 6 complexes showed low degradation points, which would make them ideal candidates for decomposition to MS2 (M = Mo, W). LRe(CO)5X (X = Cl, Br) complexes were tested for the electrolytic reduction of carbon dioxide by cyclic voltammetry and were able to reduce CO2 to CO.