prepared a new 1,2-bis(3-cyanothiophen-2-yl)perfluorocyclopentene with electro-withdrawing cyano groups at both reactive carbon atoms. Furthermore, we studied the substituent effects of the reactive carbon atoms on the photochromic properties of 1,2-bis(3-R-substituted thiophen-2-yl)perfluorocyclopentenederivatives by comparing the absorption wavelengths and quantum yields of the derivatives having R =