Synthesis of second order nonlinear optical multichromophore based on double-donors with enhanced electro-optic coefficients and thermal stability

Our work was related to the systhesis of several nonlinear optical dendrimers L1-L3 with identical Bis(N,N-diethyl)aniline-derived donor bridge and phenyl-trifluoromethyl-tricyanofuran acceptor. The dendritic structure of multichromophores can effectively reduce the electrostatic interaction between chromophores. And the strong acceptor result in large first-order hyperpolarizability of the chromophores. Multichromophores L2-L3 showed very high poling efficiencies due to large steric hindrance and first-order hyperpolarizability value of chromophores. A large poling efficiency (2.10 ± 0.08 nm2/V2) and r33 (205 p.m./V) have been achieved for neat chromophore L3 thin films at 1310 nm. Besides, the glass transition temperature (Tg) of L2 and L3 has greatly improved to 125 °C and 133 °C, respectively. All of these provided an new insights into molecular design of chromophore with enchanced poling efficiency and high thermal stability.