Activation and derivatization of metal hydride complexes via one-photon two-electron processes and the catalytic reduction of substrates for C1 chemistry

2019 Fiscal Year Final Research Report

• Project/Area Number: 16K05721
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Inorganic chemistry
• Research Institution: Osaka University
• Principal Investigator: Suenobu Tomoyoshi 大阪大学, 工学研究科, 助教 (90271030)
• Project Period (FY): 2016-04-01 – 2020-03-31
• Keywords: 触媒 / 金属ヒドリド / C1化学 / 錯体 / 光化学 / 過渡吸収 / 結晶

Outline of Final Research Achievements

The research was conducted for the purpose of developing efficient photocatalytic systems consisting of metal complexes with　appropriate catalytic reactivity that enables multi-electron reduction processes induced by the one-photon absorption with the aid of co-catalysis by suppressing hydrogen evolution. Catalytic reduction of CO2 was made possible for selective generation of C1 chemicals inspired by natural photosynthetic reaction systems.　Time-resolved spectroscopies, especially sub-nanosecond time resolution, are found to be indispensable to detect the transient species as a key intermediate for revealing the reaction mechanisms of photocatalysis studied in this research. The sustainable and green photocatalytic systems composed of metal complexes have been explored by developing molecular crystalline materials involving flexibility-controllable parts exhibiting photoresponsive dynamic properties.

Free Research Field

金属錯体光化学

Academic Significance and Societal Importance of the Research Achievements

金属錯体の光化学反応研究において、金属-配位子間結合の活性化は、これまで主に金属カルボニル錯体の光CO解離（電子遷移）や金属-金属、金属-炭素結合の光均一化開裂（１光子１電子移動過程）に関する基礎研究があるものの、金属ヒドリド錯体の光化学研究は未だ探求の余地が残されてきた。生じる配位不飽和錯体は、多くの触媒反応活性種としての利用も期待できる。金属錯体の反応性や触媒特性を最適化して水素放出を抑制し、高効率１光子多電子還元を実現することで、ギ酸、ホルムアルデヒド、メタノール等の有用C1化合物として生産できれば、枯渇性資源に依存する現代社会の、持続可能な循環型社会へのパラダイムシフトが可能となる。