Effect of substituting groups on electronic spectra and second-order nonlinear optical properties of 8-hydroxyquinolinate metal complexes

Geometry optimization of target complexes were performed at the level of B3LYP/LanL2DZ/6-31G*, and their absorption spectra and the second nonlinear optical properties were calculated at the TD-B3LYP/LANL2DZ/6-31 + + G* * level and B3LYP/LANL2DZ/6-31 + + G** level, respectively. The results indicate that the introduction of conjugated substituting groups of electron-donor and conjugated substituting groups of strong electron-accepter makes maximal absorption wavelength red-shifted and blue-shifted, respectively. The introduction of conjugated substituting groups resultes in obvious increase of Second nonlinear optical properties for IrQ(3) complexes. The electronic transfer belongs to intra-ligand charge transfer (LLCT) for AgQ complexes, and LLCT mixed with partially metal-to-ligand charge transfer for PtQ(2) and IrQ(3) complexes. There is no effect of substituting groups on transition properties for AgQ, PtQ(2) and IrQ(3) complexes.