Design and synthesis of self-assembled nonlinear optical multichromophore dendrimers with different acceptors

Abstract

Self-assembled three-arm multichromophore dendrimers H4 and H5 based on the same aniline donor and phenyl-trifluoromethyl-tricyanofuran (CF₃-TCF) or perfluorophenyl-tricyanofuran (5F-TCF) acceptor with isophorone-derived bridges were developed. In particular, a trifluorobenzyl dendron was introduced into the donor or bridge parts of the chromophores. The π–π interaction of the trifluorobenzyl dendron (TFD) could minimize the electrostatic interactions between molecules and increase the poling efficiency at high load densities. After poling, the dendrimer films H4 and H5 achieved a large electro-optic coefficient of 279 and 269 pm V⁻¹, respectively, compared to 226 pm V⁻¹ for single chromophore H2 with the same functional groups and conjugated structures. Moreover, the long-term alignment stability of chromophores was improved due to the non-covalently crosslinked network formed by the TFD–TFD π–π interactions. After 1000 h annealing at room temperature, above 95% of the initial r₃₃ values could be still maintained for the self-assembled films H2, H4 and H5. The high r₃₃ values and long-term alignment stability make them promising candidates for application in advanced photonic devices.