Discovering Functional Properties of Photo-switching Liquids Containing Photoresponsive Molecules and Ions

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K15357
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 35030:Organic functional materials-related
• Research Institution: Wakayama National College of Technology (2021-2022); Tokyo University of Science, Yamaguchi (2020)
• Principal Investigator: Yusuke Funasako 和歌山工業高等専門学校, 生物応用化学科, 助教 (20734312)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: イオン液体 / スピロピラン / フォトクロミズム / 光応答性 / プロトン移動 / 熱物性 / 結晶構造 / 結晶内空間

Outline of Final Research Achievements

Photochromic ionic liquids containing spiropyrans and diarylethenes were developed. The spiropyran and diarylethene salts containing imidazolium group, and the salts obtained from 1:1 mixture of spiropyran photoacid and organic superbase were synthesized and their thermal properties and photochromic properties were revealed. In the crystalline spiropyran salts with high melting points, the reaction cavities of crystal structure were controlled by chemical pressure and physical hydrostatic pressure, and the relationship between the cavity changes and the crystalline-state photochromism of the salts was investigated.

Free Research Field

機能物性化学

Academic Significance and Societal Importance of the Research Achievements

フォトクロミック分子骨格を有するイオン液体はこれまで内外で盛んに研究されてきたが、静電相互作用変化を伴った光異性化を示す本系は原理が大きく異なる。したがって、光による多彩な液体物性の変化が期待される。本課題で新しく発見した光酸発生型スピロピラン系イオン液体は、イオン液体の機能化を従来の疎水性イオン液体だけでなく、プロトン性イオン液体にも拡張できる可能性を有している。このような液体は、多彩な物性研究の新対象となるだけでなく、機能溶媒用途といった応用展開にもつながる。