Synthesis of phenyltetraene chromophores-based hybrid materials for large nonlinear optical activity

摘要

Two new chromophores, CLDS1 and CLDS2, based on a similar D-π-A structure as the phenyltetraene chromophore CLD, but with an alkylthio group perpendicular to the direction of the long molecular axis as isolation spacer were synthesized. Through a urethane forming reaction between 3-isocyanatopropyltriethoxysilane (ICTES) and chromophores, the alkoxysilane dyes were synthesized. Subsequently, a series of transparent and homogeneous inorganic-organic hybrid films were prepared via a sol—gel process of the alkoxysilane dye with triethoxyvinylsilane. The molecular structures of the resultants were confirmed by ~1H NMR, FTIR and UV-visible spectra. After electric poling, the nonlinear optical coefficients (d_(33)) of the hybrid films F-CLDS1 and F-CLDS2 were determined to be 104.54 and 98.17 pm V~(-1), respectively, which are almost 3 times the d_(33) value of hybrid film containing CLD (37.78 pm V~(-1)), indicating that the incorporation of alkylthio group can efficiently improve the macroscopic optical nonlinearities of hybrid materials.