A study for coupling phenomena of proton transfer with physical or chemical properties of molecular solids, based on Kagome-type porous molecular conductors

2022 Fiscal Year Final Research Report

• Project/Area Number: 19K15590
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 34010:Inorganic/coordination chemistry-related
• Research Institution: Nagasaki University
• Principal Investigator: Hayashi Mikihiro 長崎大学, 教育学部, 助教 (40771225)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: 水素結合 / プロトン移動 / 金属錯体 / 分子結晶 / 電子移動 / エネルギー移動

Outline of Final Research Achievements

This study was aimed for constructing molecular solids of d-π hybridized metal complexes, that offer mobile protons along hydrogen bond (H-bond) to regulate their electronic states responsible for physical or chemical properties. To carry out this study, topochemical approaches were adopted in synthesis of solids requiring protonation and oxidation processes. The first oxidative crystallization successfully afforded Kagome-type porous conductors showing an electron correlation, but their following protonation of using the pores caused electron transfer to collapse the structure. As for the first protonation, co-crystallizing with a photo-oxidative proton donor gave sheet-type H-bond crystals, and the following photoirradiation leaded to an unexpected photostability of the sheet owing to a cooperative phenomenon of proton transfer and energy transfer. The photostability was modifiable by d-element exchanges, which indicates a contribution of d-element to the coupling.

Free Research Field

錯体化学

Academic Significance and Societal Importance of the Research Achievements

本研究により、π電子系有機分子に留まっていたプロトン－電子連動に基づく物質開発を、d－π混成電子系金属錯体に拡張した。これにより、重点的に開拓されてきたプロトンダイナミクスとπ電子物性の境界研究領域にdブロック元素の寄与が持ち込まれ、新たな研究分野へ発展する可能性がある。また、従来から金属錯体に期待される磁性や低エネルギー光物性、レドックス触媒活性を活かした応用分野と、注目度の高い水素エネルギー分野との親和性が高まり、エネルギー問題解決や高度情報化社会に役立つ分子材料の開発が活発化する可能性を秘める。