Developments of Oxygen Evolving Complex Catalysts Aiming for Energy Conversion

四电子水氧化是实现人工光合作用的必要条件。 在本研究中，我们开发了单核和双核配合物催化剂，用于平衡电位附近的四电子水氧化。 我们合成了具有强给电子配体的单钌配合物，如四甲基乙二胺（tmen）或二吡啶基苯（dpb）。 与具有电子受体配体的相应钌络合物相比，这些单钌络合物在较低的电势下被氧化。 事实上，这些配合物在[Ru（boy）]3+（bpy = bipyridine）作为氧化剂的存在下催化了水的氧化。 此外，我们还合成了含磷酸基团的双核钌配合物，以开发金属氧化物-金属配合物复合催化剂。 电化学测试表明，双核钌配合物修饰在ITO电极上表现出可逆的氧化还原反应。

Four-electron water oxidation is a necessary for realization of artificial photosynthesis. In this research, we developed mono- and binuclear complex catalysts for the purpose of four-electron water oxidation near the equilibrium potential. We have synthesized the mono-ruthenium complexes having a strong electron donor ligand, such as tetramethylethylenediamine (tmen) or dipyridylbenzene (dpb). These mono-ruthenium complexes have been oxidized at lower potential compared with that of the corresponding ruthenium complex having the electron acceptor ligand. In fact, these complexes have catalyzed water oxidation in the presence of [Ru(boy)]3+ (bpy = bipyridine) as an oxidant. Furthermore, we synthesized dinuclear ruthenium complex with a phosphate group in order to develop the hybrid catalyst of metal-oxide and metal complex. Electrochemical measurements have revealed that the dinuclear ruthenium complex modified on ITO electrode shows reversible redox reaction.