Shiyoshi Yokoyama,* Tatsuo Nakahana, Akira Otomo, and Shinro Mashiko Nonlinear optical dendritic macromolecules, called azobenzene dendrons, were synthesized, and their conformational properties and molecular nonlinear optical properties were clarified by second-order nonlinear optical measurement. The synthesized molecules were modified by introducing 1-15 numbers of azobenzene branching units as the nonlinear optical chromophore and by placing aliphatic chains at the end the dendritic chains. In these topologically complex molecules, each chromophore contributed coherently to the macroscopic nonlinear optical activity. The first-order molecular hyperpolarizability of the azobenzene dendron having 15 chromophoric units was measured to be 3010 ![]() ![]() |