Substitution Effect on the Coloration Quantum Yield of a Photochromic Bisbenzothienylethene

Abstract
Introduction of isopropyl substituents to 2 and 2′ positions of benzothiophene rings of bis(1-benzothiophen-3-yl)hexa-fluorocyclopentene increased the population of anti-parallel conformation, and enhanced the quantum yield of the cyclization reaction.