Synthesis of coordination networks using ionic liquids as precursors and their application to proton conductors

2023 Fiscal Year Final Research Report

• Project/Area Number: 22K19064
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 35:Polymers, organic materials, and related fields
• Research Institution: Kyoto University
• Principal Investigator: Horike Satoshi 京都大学, 理学研究科, 教授 (70552652)
• Project Period (FY): 2022-06-30 – 2024-03-31
• Keywords: イオン液体 / 配位高分子 / 相転移 / ガラス / イオン伝導

Outline of Final Research Achievements

Ionic liquid is a general term for salts composed of cations and anions with a melting point of less than 100°C. In this study, new coordination polymers were synthesized using ionic liquids as precursors, and their phase transition properties, structures, and physical properties were investigated to find the differences from conventional coordination polymers and their material performances. The synthesis of coordination polymers using ionic liquids under various conditions revealed that various coordination polymers were obtained, especially those in which the anions constituting the ionic liquid bridged metal ions. Many of them have high dynamic properties at room temperature, and a wide range of crystal melting is observed at temperatures below 150℃. Using these properties, we have evaluated their macromolding (e.g., membranes and fibers), porosity, and conductivity, and found their complex functions.

Free Research Field

錯体化学

Academic Significance and Societal Importance of the Research Achievements

イオン液体と配位高分子の学問領域は一般的に大きく分けられており、それらを互いに見据えながら新物質を合成する研究は限られていた。本研究成果により、イオン液体が広く配位高分子の合成に活用できる指針を与えられた。またイオン液体特有の小さい静電相互作用や多様な分子配座を配位高分子構造に組み込むことができるため、より低い融点、あるいは内部自由度を上げることによるガス透過やイオン伝導性を与えられることを見出した。膜やファイバー状で選択的なガス透過や伝導性を発現することは、マクロ材料応用において結晶では難しい特徴であり、材料としての可能性も大きく引き上げる結果である。