Kitagawa Daichi, Mori Takahito, Sawa Hikaru, Hamatani Shota, Kobatake Seiya
Department of Chemistry and Bioengineering, Graduate School of Engineering, Osaka Metropolitan University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka, 558-8585, Japan.
Chemistry. 2025 May 27;31(30):e202501077. doi: 10.1002/chem.202501077. Epub 2025 Apr 28.
Molecular photoswitches have attracted significant attention due to their potential applications in materials science and life science. In this study, we synthesize a series of aza-diarylethenes incorporating benzazole groups as the nitrogen atom source for 6π azaelectrocyclization and investigate their photochromic behaviors. Compounds 1-3, bearing benzothiazole, benzoxazole, and benzimidazole groups, exhibit thermally reversible type photochromism with thermal back reaction half-lives (t) ranging from milliseconds to seconds at 293 K. Additional derivatives 4-6 with benzothiophene-S,S-dioxide at the ethene bridge moiety further expand the range of thermal back reactivity, with t values extending up to tens of minutes. Quantum chemical calculations confirm that the variation in thermal back reactivity is governed by the energy difference between open- and closed-ring isomers, in accordance with the Bell-Evans-Polanyi principle. These findings provide a molecular design strategy for controlling the thermal back reactivity of aza-diarylethenes, enabling further development of functional photochromic materials.
分子光开关因其在材料科学和生命科学中的潜在应用而备受关注。在本研究中，我们合成了一系列含有苯并唑基团作为6π氮杂电环化氮原子源的氮杂二芳基乙烯，并研究了它们的光致变色行为。带有苯并噻唑、苯并恶唑和苯并咪唑基团的化合物1-3表现出热可逆型光致变色，在293 K时热逆反应半衰期（t）从毫秒到秒不等。在乙烯桥部分带有苯并噻吩-S,S-二氧化物的另外几种衍生物4-6进一步扩大了热逆反应性的范围，t值延长至数十分钟。量子化学计算证实，根据贝尔-埃文斯-波拉尼原理，热逆反应性的变化受开环和闭环异构体之间的能量差控制。这些发现为控制氮杂二芳基乙烯的热逆反应性提供了一种分子设计策略，有助于功能光致变色材料的进一步发展。
