Novel Dendritic Chromophores for Electro-optics: Influence of Binding Mode and Attachment Flexibility on Electro-optic Behavior

Four dendritic electro-optic (EO) chromophores were designed, prepared, and evaluated to explore the effects on EO behavior of end-on relative to side-on chromophore attachment geometry as well as differing chromophore-to-dendrimer core tether groups. Composite samples of APC and dendritic chromophores were found to exhibit considerably more thermally stable EO properties as compared to samples of the corresponding isolated chromophore. Side-on type binding geometry was found most thermally stable, requiring larger thermal activation energies to induce dipole randomization. Incorporation of a long, flexible chromophore−core tether group greatly enhanced average EO coefficients of the dendritic systems.