A novel donor-acceptor （D-A） triphenylamino terpyridine derivative L was facilely synthesized and fully characterized, and its single crystals were obtained and determined by X-ray diffraction analysis. It crystallizes in triclinic, space group P/ with a = 11.760（5）, b =12.516（5）, c = 12.850（5） A, α = 67.141（5）, β= 65.284（5）, γ = 75.876（5）°, Mr = 621.54, F= 1575.6（11） A3, Z= 2, Dc = 1.310 g/cm3,μ = 0.245 mm-1, F（000） = 648, the final R = 0.0671 and wR = 0.1869 for 11328 observed reflections with 1〉 2σ（I）. Linear and nonlinear optical properties of terpyridine derivative L were systematically investigated. The maximum two-photon cross-section of L was 382.5 GM （Goeppert-Mayer）, measured by two-photon excited fluorescence （TPEF） method. This result demonstrates that the increase of intramolecular charge transfer （ICT） leads to enhanced two-photon absorption （2PA）, which could be achieved by introducing additional electron-donor groups to the molecular framework.
A novel pyrazole derivative ligand, BTA（BTA = bis-（4-ethoxy-phenyl）-[4-（tripyrazol-1-yl-methyl）-phenyl]-amine）, was synthesized and fully characterized by 1H-NMR, MALDI-TOF-MS spectra and single-crystal X-ray diffraction analysis. It crystallizes in triclinic, space group P1, with a = 11.827（1）, b = 16.000（2）, c = 16.527（2）A, α = 108.510（1）, β = 91.116（5）, γ = 101.734（1）°, V = 2894.5（6） A3, Z = 1, Dc = 1.262 g/m^3, F（000） = 1162, Μr = 545.63, μ = 0.083 mm-1, the final R = 0.0728 and w R = 0.2213 for 7541 observed reflections with I 〉 2（I）. The structural analysis revealed that three pyrazole units are attached to the same carbon atom connected with bis-（4-ethoxy-phenyl）-phenyl-amine group. UV-vis spectral features of the ligand in various solutions were explained by time dependent density functional theory（TD-DFT）. It was also found that the ligand（BTA） exhibits an exclusively selective and sensitive response toward Fe3＋ using UV-vis spectroscopic method.
