Photochemistry and photoorientational phenomena in carbosilane dendrimers with terminal azobenzene groups

Full Paper: Photo-optical properties of carbosilane dendrimeis of the first, third, and fifth generations with terminal azobenzene groups are presented. The dendrimers synthesized display a crystalline phase, which melts into isotropic liquid at 81-91degreesC (depending on the generation number). A comparative analysis of the photo-optical lehaviour of the dendrimers in dilute solutions and films was carried out. It was shown that under the action of UV irridation (365 nm) an E/Z photoinduced isomerization of azobenzene groups takes palce in the solutions and amorphous films. This process was found to be thermally reversible: annealing leads to a back Z/E isomerization. The processes of photoinduced orientation of terminal azobenzene groups of the dendrimers under the action of polarized UV light (365 nm) were studied.