Novel Materials for Large Change in Refractive Index: Synthesis and Photochemical Reaction of the Ladderlike Poly(silsesquioxane) Containing Norbornadiene, Azobenzene, and Anthracene Groups in the Side Chains

We succeeded in the synthesis of certain poly(silsesquioxane)s (poly(SCC)) with excellent refractive indices properties, which have pendant norbornadiene (NBD), azobenzene (AZ), and anthracene (AT) moieties. The photochemical reactions of the obtained poly(SCC) derivatives were examined in the film state upon UV irradiation, and it was found that poly(SCC) derivatives with NBD groups, AZ groups, and AT groups had large change in values of the refractive index (Δ n D 's) before and after photoirradiation which were in the range of 0.050−0.073, 0.007−0.009, and 0.094−0.116, respectively.