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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.

A curcumin derivative ligand, 1,7-bis（3-methoxyl-4-acetoxyl）phenyl-1,6-heptadiene-3,5-diketone （diacetylcurcumin, abbrevi- ated as HL）, and its Cu and Ni complexes have been synthesized and fully characterized by elemental analyses, IR, 1HNMR and molar conductivity. The resulting complexes exhibit two-photon excited fluorescence （TPEF） in DMF, and have been proven to be potentially useful for two-photon microscopy imaging in living cells. In addition, cytotoxicity tests showed that the low-micromolar concentrations of ML2 did not cause significant reduction in cell viability over a period of at least 24 h and should be safe for further biological studies.