Response surface method is applied here to trace the photochromic path and explore the substituent and β-cyclodextrin effects on the decoloration of the spiropyran/β-cyclodextrin polymer (SP/CDP) complex. Calculations support the ultraviolet/visible experimental results, suggesting that introducing an electron-withdrawing group to the benzopyryl moiety of SPs favors an enhancement in their decoloration, whereas replacing the benzopyryl with a naphthopyryl moiety obstructs their decoloration. CDP complexation weakens the C1O bond of the closed SP form and enhances the polar zwitterionic structure in the open photomerocynine form. However, the electron-withdrawing group strengthens the interaction of benzopyryl SPs with CDP, thereby hindering their decoloration.
Chemical Physics Letters, Volume 662, Pages 296-305