Synthesis,photophysical properties and TD-DFT calculation of four two-photon absorbing triphenylamine derivatives

In this study,linear absorption,single-photon excited fluorescence,fluorescence quantum yields,fluorescence lifetime and two-photon excited fluorescence of a series of triphenylamine derivatives （L1,L2,L3 and L4） have been measured.L1 and L3 are D--A type dyes,while L2 and L4 are D--D--A type dyes （D=donor,A=acceptor）.The investigated compounds consist of triphenylamine-bearing donor-substituted and/or systematically extended-conjugated length,which are designed to gain insight into the effect of the ethoxyl unit and-linkage length on the linear and nonlinear optical properties.The influence of solvent polarity on the photophysical properties was investigated.Employing time-dependent density functional theory （TD-DFT） calculations,the structure-property relationships are discussed.