Photochromism of new diarylethene derivatives based on the hybrid photochromic skeleton of benzofuran and benzene moieties

Abstract Four new photochromic diarylethenes with both benzofuran and benzene moieties were synthesized, and the structures of three diarylethenes were determined by single-crystal X-ray diffraction analysis. The six-membered benzene ring was connected directly to the central perfluorocyclopentene unit as an aryl moiety and available to participate in photoisomerization reaction. All the diarylethenes exhibit favorable photochromism and function as notable fluorescence switches in both hexane and poly(methyl methacrylate) films. The electron-donating substituents effectively enhanced the cyclization quantum yields, while the electron-withdrawing substituents notably shifted the fluorescent emission peaks to a longer wavelength in both solution and poly(methyl methacrylate) films. The result indicated that the different substituents linked at the reactive carbon atom of the benzene moiety had a significant effect on their optical and electrochemical properties.