New Transition Metal Chemistry With Phosphino-Thiol Ligands

Abstract

Hydrogenases are a class of enzyme with the unique ability to catalytically reduce or oxidize hydrogen. Due to this ability they have received much attention from chemists who want to harness this power in a controlled setting. This power will allow not only for the mass production of hydrogen but also the potential for the production of cheaper catalysts to be used in fuel cells. The focus of this research is to create different models for the active site of hydrogenase based around the nickel center of the [NiFe] class of hydrogenase. It is believed that this nickel center is responsible for catalytically producing dihydrogen from two protons and two electrons. Currently no model has the ability to perform this at an efficient rate.This work primarily uses the potentially tridentate bis(2-thiophenyl)phenylphosphine ligand, or H2[PS2], for short. This ligand represents the sulfur rich environment of the nickel with its two thiol functional groups, and has shown prior success in making stable metal complexes at a few different oxidation states. Metal complexes of vanadium, chromium, and manganese containing this ligand were successfully synthesized and characterized using single crystal X-ray diffraction, cyclic voltammetry, and ultraviolet-visible spectroscopy.