Photoisomerization of 1-phenyl-2-(pyridin-2-yl)indole BMes2: The dark isomer

Hazem Amarne, Chul Baik, Rui Yao Wang, Suning Wang*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

41 Citations (Scopus)


A new member of photochromic N,C-chelate organoboron compounds, BMes2(Py-N-Ph-In) (1), where Mes = mesityl, Py-N-Ph-In = 1-Ph-2-(2-Py)-indolyl, has been synthesized, and its photo-thermal isomerization properties have been investigated. Upon irradiation by UV light (365 nm), compound 1 isomerizes to compound 1a, changing color from light yellow to dark turquoise-green with the disappearance of the green fluorescence of 1. This process involves the breaking/formation of a B-C bond and a C-C bond and is thermally reversible. Compound 1a finally allowed us to obtain suitable crystals. The crystals of the dark isomer 1a were isolated, and its structure was determined by a single-crystal X-ray diffraction analysis, which confirms the formation of a C-C bond between the indolyl ring and a mesityl ring, the dearomatization of the mesityl ring, and the presence of a BC2 triangle in 1a. NMR and DFT computational data further support that 1a is an analogue of the dark isomers generated from previously reported N,C-chelate BMes2 compounds.

Original languageEnglish
Pages (from-to)665-668
Number of pages4
Issue number4
Publication statusPublished - 28 Feb 2011
Externally publishedYes


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