Synthesis and characterization of triphenylamino-substituted chromophores for nonlinear optical applications

Two triphenylamino-substituted chromophores containing hydroxy group, which can be easily incorporated into polymer backbone or sol–gel matrix through covalent bond, were synthesized via Vilsmeier–Haack reaction and Knoevenagel condensation. These stilbene-type chromophores with different electron acceptors were characterized by elemental analysis, 1H NMR, FTIR, UV–vis spectra and thermogravimetric analysis (TGA). The hyperpolarizabilities were characterized through solvatochromic method. Compared with commercially available nonlinear optical dyes such as C.I. Disperse Red 1 (DR1), C.I. Disperse Orange 3 (DO3) and C.I. Disperse Red 19 (DR19), triphenylamino-substituted chromophores possess higher thermal stability and display better transparency in operating wavelength of electronic devices.