Molecular Conversion Using One-Step Multi-electron Transfer Complex

钒（salen）多核配合物作为电子介质，允许催化多电子电析出氧。通过调节氧化还原电位的值接近的热力学势的4-电子还原的氧使用各种配体，本研究的目的是建立多电子还原系统的分子氧使用这些配合物作为电子介体。第一年，我们制备了含惰性配体的钒配合物，并测定了它们的氧化还原电位。并制备了相应的双核配合物。这些复合物的X射线研究揭示了这些复合物中的氧结合位点的结构。通过近红外光谱测定了配合物的氧化还原状态。催化剂氧化反应动力学分析表明存在μ-二氧代中间体。第二年，选择钒配合物作为电子媒介物，考察了氧的还原反应。通过旋转环盘伏安法得到的Koutecky-Levich图揭示了4电子过程和水的产生。测定催化剂的转化数超过10。建立了氧的选择性四电子还原体系。

Vanadyl (salen) multi-nuclear complexes act as electron mediators to allow catalytic multi-electron electroeduction of oxygen. By adjusting redox potentials to the value close to the thermodynamic potential for the 4-electron reduction of oxygen using a variety of ligands, the objective of the present study is to establish multi-electron reduction systems of molecular oxygen by the use of these complexes as electron mediators. It is also intended to elucidate novel molecular conversion systems by the use of these complexes as oxidation systems for organic substrates.It the first year, vanadium complexes with inert ligands were prepared and the redox potentials were determined. Also, the corresponding dinuclear complexes were prepared. X-ray studies of these complexes revealed the structure of the oxygen-binding sites in these complexes. By near-infrared spectrum, the redox state of the complexes were determined. Kinetic analysis for the oxygenation of the catalyst revealed the presence of mu-dioxo intermediate.In the second year, the selected vanadium complexes were used as electron mediators, and the reduction of oxygen was examined. Koutecky-Levich Plots obtained by the rotating ring-disk voltammetry revealed the 4-electron process and the production of water. The turn-over number of the catalyst was determined to exceed 10. It was concluded that selective 4-electron reduction system of oxygen was established.