Mimicking Metal Complexes Involved in Biological Process for Application in Green Energy Production

Metal complexes that play important roles in regulating redox processes in biological and synthetic systems have attracted great attention from chemists, biologists and material scientists. Investigating the detailed processes of their reactivities is essential for us to understand how the functions of the metal complexes depend on the choice of the metal atoms, coordination environment of the metal centers and the supporting facility of the complexes. Hopefully in the future, efficient alternative catalysts can be designed and synthesized. In nature, the oxygen-evolving complex, Mn4O5Ca, in Photosystem II is the active site in catalytically converting water molecules to oxygen gas. A similar bio-inspired metal complex, MnVoxo, was able to mimic this function. Many other metal complexes have also been explored as artificial photosynthesis systems. Inspired by the mechanism of Cytochrome P450s in functionizing C-H bonds, a non-heme complex consisting of an FeIV-oxo center has achieved such chemical transformation as well. The bio-inspired approach in designing new metal catalysts for oxygen reduction has also led to the success of several metal catalysts utilized toward the development of fuel cells. In our research group, polydentate tripodal ligands were applied toward catalyst design and reactivity examination. One of the ligands was capable in stabilizing a single Ni core with three secondary basic ligand groups surrounding it. The immediate plan is to to study the reactivity and install other transition metal cores. Examination of how the basic framework influences the reactivities that the metal center exhibits will also be described