Synthesis and photochromism of 1,2-bis(5-aryl-2-phenylethynylthien-3-yl)hexafluorocyclopentene derivatives

Photochromic dithienylethenes that possess elements of lipid complementarity, and undergo large, photoinduced changes in molecular geometry have been prepared. Further, a regioselective approach has been developed for the preparation of dithienylethenes containing phenylethynyl and various aryl substituents at C2 and C5 of the thiophene moieties, respectively. The prepared photochromic compounds were observed to undergo reversible photoisomerization. Their absorption properties, reaction quantum yields, and photoconversions were determined in n-hexane.