Photon-Quantitative 6π-Electrocyclization of a Diarylbenzo[b]thiophene in Polar Medium was written by Li, Ruiji;Nakashima, Takuya;Galangau, Olivier;Iijima, Shunsuke;Kanazawa, Rui;Kawai, Tsuyoshi. And the article was included in Chemistry – An Asian Journal in 2015.Computed Properties of C8H4Br2S This article mentions the following:
The high reactivity of 6π-electrocyclization in polar solvents has remained one of the important challenges for diarylethenes because of the emergence of a twisted intramol. charge transfer (TICT) state at the excited state in such polar media, which usually quenches the photocyclization reaction. Herein the authors report on the preparation and highly efficient photocyclization of 2,3-diarylbenzo[b]thiophenes with nonsym. side-aryl units in a polar solvent. While the dithiazolylbenzo[b]thiophene showed a suppressed quantum yield of 6π-electrocyclization of 54% in methanol, the replacement of a thiazole unit with a thiophene ring led to a photon-quant. 6π-cyclization reaction. The nonsym. modification into the side-aryl units was considered to enhance the CH/π interactions between side-aryl units to support a photoreactive conformation in methanol. The stabilization of the photochromic reactive conformation is expected to suppress the formation of the TICT state at the excited state, leading to highly efficient photoreactivity. In the experiment, the researchers used many compounds, for example, 2,3-Dibromobenzo[b]thiophene (cas: 6287-82-7Computed Properties of C8H4Br2S).
2,3-Dibromobenzo[b]thiophene (cas: 6287-82-7) belongs to benzothiophene derivatives. Benzothiophene is relatively a stable molecule. The core structure is a part of various pharmaceutical substances and natural products. It is found within the chemical structures of pharmaceutical drugs such as raloxifene, zileuton, sertaconazole, and also BTCP.Computed Properties of C8H4Br2S
Referemce:
Benzothiophene – Wikipedia,
Benzothiophene | C8H6S – PubChem