Synthesis of poly(spiropyran)s by polycondensation and their photoisomerization behaviors

Poly(spiropyran)s were synthesized by polycondensation of a bis(indoline) monomer with bis(o-positioned formyl and hydroxy)-substituted aromatic monomers in alcoholic solvents. The structures of the products and their molecular weights were determined by the 1H NMR and GPC measurements, respectively. Furthermore, photoisomerization behaviors of the poly(spiropyran)s were analyzed by the UV–Vis and 1H NMR measurements of their solutions in dichloromethane upon the UV and visible light irradiations.