Abstract Certain unsymmetrical 1, 2-bis (dithienyl) perfluorocyclopentenes have been synthesized containing alkylthio, bromo, carboxy, and benzothiazolyl substituents in the thiophene rings. It was shown that on irradiation with UV light they all display photochromic properties, with the exception of the derivative containing an alkylthio group in the reaction center of one of the thiophene rings.
