Synthesis and photochromic behavior of bi-functional photochromic compound

Bi-functional photochromic compound (SpAz) was synthesized with spirobenzopyran and azobenzene derivatives by DCC coupling reaction. In chloroform solution, a novel photochromic compound showed four kinds of isomer depending on the wavelength of the light irradiated. It was suggested that SpAz has four digital codes for optical memory. When SpAz was dispersed in poly(methyl methacrylate), on the other hand, the photoisomerization of SpAz was limited in polymer matrix due to the poor mobility of Azobenzene moiety with high steric hindrance.