Photochromic polymers bearing various diarylethene chromophores as the pendant: synthesis, optical properties, and multicolor photochromism

Photochromic polymers with various diarylethene derivatives were synthesized by a conventional radical polymerization of styrene derivatives having diarylethene chromophores as the pendant. All the polymers exhibited reversible photochromism in the film as well as in solution, while the photocyclization conversion in the film decreased in comparison with that in solution because of a restriction of the conformational structure in the solid state. Although the photocyclization and photocycloreversion quantum yields at the initial stage of the reactions in the film were comparable to those in solution, the apparent cycloreversion quantum yield decreased along with the reaction, which is derived from a distribution of the quantum yields in the solid state. Finally, the photochromic terpolymers consisting of three diarylethene monomers which show photochromism changing color to cyan, magenta, and yellow were synthesized. The terpolymers were demonstrated to show bright colors including black, green, red, and blue both in solution and in the solid state by selective bleaching processes. Such multicolor photochromic polymers composed of diarylethene derivatives have a potential for rewritable photochromic display devices.