Yamada Mihoko, Sawazaki Tomoya, Fujita Mae, Asanoma Fumio, Nishikawa Yoshiko, Kawai Tsuyoshi
Division of Materials Science, Nara Institute of Science and Technology, NAIST, Ikoma, Nara, 630-0192, Japan.
Chemistry. 2022 Sep 1;28(49):e202201286. doi: 10.1002/chem.202201286. Epub 2022 Jul 13.
We have designed and synthesized photochromic tetrathienyl corannulene compounds, 1,2,7,8-tetrakis(2-methyl-5-phenylthiophen-3-yl)corannulene (1) and 1,2,7,8-tetrakis(2,4-dimethyl-5-phenylthiophen-3-yl)corannulene (2), by fusing two units of photochromic terarylene with a curved aromatic corannulene with a promising antenna effect. Compound 1 exhibited highly sensitive photoreactivity, with a large molar absorption coefficient of 8.2×10 M cm and practically photon-quantitative photocyclization. On the other hand, a terarylene derivative with a planar aromatic phenanthrene, 9,10-bis(2,4-dimethyl-5-phenylthiophen-3-yl)phenanthrene (4) showed no photoreactivity. The reason for such a difference was attributed to the predominance of the photoreactive atropisomers amplified by energy migration, and the shortened distance between reactive carbons induced by the curved structure.
我们通过将两个光致变色三联苯单元与具有良好天线效应的弯曲芳香族碗烯融合，设计并合成了光致变色四噻吩基碗烯化合物，即1,2,7,8-四（2-甲基-5-苯基噻吩-3-基）碗烯（1）和1,2,7,8-四（2,4-二甲基-5-苯基噻吩-3-基）碗烯（2）。化合物1表现出高度灵敏的光反应性，其摩尔吸收系数高达8.2×10⁴ M⁻¹ cm⁻¹，并且具有近乎光子定量的光环化反应。另一方面，具有平面芳香族菲结构的三联苯衍生物9,10-双（2,4-二甲基-5-苯基噻吩-3-基）菲（4）则没有光反应性。这种差异的原因归因于通过能量迁移放大的光反应性阻转异构体占主导地位，以及弯曲结构导致的反应性碳原子之间距离缩短。
