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

Abstract

Abstract 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 1 H 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.