Photo-reactivity of 6-electron cyclic photochromic molecules with different sequences

2022 Fiscal Year Final Research Report

• Project/Area Number: 19K05639
• 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: Niihama National College of Technology
• Principal Investigator: Takami Shizuka 新居浜工業高等専門学校, 環境材料工学科, 教授 (70398098)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: フォトクロミズム / 光反応量子収率 / 熱安定性 / 蛍光量子収率

Outline of Final Research Achievements

In this study, we focused on AAE- and AEE-type photochromic molecules in order to clarify the correlation between the photoreactivity of 6πelectron cyclic photochromic molecules and the arrangement of the moieties constituting the molecules. The AAE-type photochromic molecule was able to retain high photoreactivity due to intramolecular interactions. Furthermore, both isomers emit fluorescence, an achievement that will lead to applications in organic EL devices and fluorescent marker materials. (2) In order to obtain stable yellow photochromic materials, we also focused on the AEE-type skeleton. The yellow-colored material showed a high photoconversion rate, was sufficiently photostable, and showed no thermal fading for more than 240 hours at 80°C. The yellow-colored material was stable enough to be used as a photochromic material. From the above, we believe that recombination of A and E sequences will lead to the synthesis of photochromic molecules with specific functions.

Free Research Field

有機化学、光化学

Academic Significance and Societal Importance of the Research Achievements

本研究結果より、AAE型分子はフォトクロミズムに伴い蛍光色が変化し、両方の異性体より異なる蛍光を発することを見出した。これは、類似骨格のAAA型やAEA型には見られない特徴であり、原因究明にはまだ解明していくべき点が多々ある。本研究は、「6π電子系分子の光反応性は分子を構成する共役部位の種類や組合せに依存し相関性が導ける」という学術的意義を示した内容である。また、光反応性を制御できるフォトクロミック分子合成の知見が分子骨格の配列から得られると、特異的機能を有する光機能性有機分子合成に繋がり、その波及効果は理論化学、構造有機化学、有機物性化学、有機機能材料化学等、多くの分野に及ぶと予想される。