The TD-DFT theory method has been used to investigate the electronic spectra and second-order nonlinear optical properties of 8-quinolinolate complexes liganded with transition metals in IB, IIB and VIIIB groups. The results show that adulteration with the transition metal can make the energy gaps of complexes smaller and the largest absorption wavelength red-shift by about 150～200 nm. Electronic transition from the ground state to excited state is p→p*, n→p* transitions, belonging to LLCT, MLCT. The IB and VIIIB group metal complexes MQ and MQ3 have displayed good nonlinear optical properties.

Key words: 8-quinolinolate metal complex, electronic spectra, second-order nonlinear optical property, density functional theory