Development of electric conductive and lustrous materials synergetically using halogen features

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K05642
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 35030:Organic functional materials-related
• Research Institution: Chiba University
• Principal Investigator: MATSUMOTO Shoji 千葉大学, 大学院工学研究院, 准教授 (50302534)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 電気伝導性 / ハロゲン結合 / ヨウ素 / チオアミジウム塩 / チアゾロイソキノリニウム塩 / チアゾリウム－3－オラート / ヒドロキシイミダゾピリジニウム / 双性イオン

Outline of Final Research Achievements

We synthesized thioamidium salts, thiazoloisoquinolinium salts, and thiazoium-3-olate bearing iodine atom. By investigation of their electric conductivity with or without iodine vapor, we found that all compounds showed the electric conductivity over 10 to the power of -9 S/cm under iodine vapor conditions. We revealed that the halogen-halogen interactions in the crystal structures were important to increase the electric conductivity. Unfortunately, we could not obtain the lustrous compounds with or without contacting iodine molecules. We also investigated the hydroxyimidazopyridinium zwitterions which was converted sulfur atom into nitrogen atom in the compound with lustrous color under the complexation of iodine molecules. Although the hydroxyimidazopyridinium compounds did not show the lustrous color, the compounds gave higher electric conductivity (10 to the power of -3 S/cm) than the compounds with sulfur atom (10 to the power of -6 S/cm) under iodine vapor conditions.

Free Research Field

合成有機化学・機能材料科学

Academic Significance and Societal Importance of the Research Achievements

本研究は，ヨウ素の酸化能とハロゲン結合能を協同的に利用することで電気伝導性を達成しており，さらにハロゲン結合の変化が物理的性質に影響を与えたことを示した初めての事例である。このことで，ハロゲン結合が単なる結合様式の一種にとどまらず，物性変化へも強く関与することを示すことができた。また，多様な骨格へと研究を広げることで，非金属による電気伝導性材料開発への多くの知見が得られた。主にヨウ素について研究することで，日本由来の資源であるヨウ素の有効活用とポテンシャルについて発信することができた。