Tetrathienyl Corannulene Compounds with Highly Sensitive Photochromism

Mihoko Yamada; Tomoya Sawazaki; Mae Fujita; Fumio Asanoma; Yoshiko Nishikawa; Tsuyoshi Kawai

doi:10.1002/chem.202201286

Tetrathienyl Corannulene Compounds with Highly Sensitive Photochromism

Chemistry. 2022 Sep 1;28(49):e202201286. doi: 10.1002/chem.202201286. Epub 2022 Jul 13.

Authors

Mihoko Yamada¹, Tomoya Sawazaki¹, Mae Fujita¹, Fumio Asanoma¹, Yoshiko Nishikawa¹, Tsuyoshi Kawai¹

Affiliation

¹ Division of Materials Science, Nara Institute of Science and Technology, NAIST, Ikoma, Nara, 630-0192, Japan.

PMID: 35707947
DOI: 10.1002/chem.202201286

Abstract

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 8.2×10⁴ M^-1 cm^-1 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.

Keywords: atropisomerism; corannulenes; energy migration; photochromism; strained molecules.

Abstract

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