Preparation,Structure, Fluorescence,Semiconductor Properties and TDDFT Calculation of a Mononuclear Zinc Complex with Mixed Ligands

A novel zinc complex[ZnL(bipy)(H2O)]×H2O with mixed ligands of 3-hydroxy-2-methylquinoline-4-carboxylic acid(HL)and bipy(bipy=2,2'-bipyridine)was synthesized by solvothermal reaction and its crystal structure was determined by single-crystal X-ray diffraction technique.The title compound crystallizes in the orthorhombic system of Pbca space group,and exists as an isolated mononuclear complex.The intermolecular hydrogen bonds and strongπ…πstacking interactions form a three-dimensional(3-D)supramolecular network.Solid-state photoluminescence spectrum reveals that it shows an emission in the blue region of the light spectrum.Time-dependent density functional theory(TDDFT)calculations reveal that this emission can be attributed to ligand-to-ligand charge transfer(LLCT).Solid-state diffuse reflectance data show that there is a narrow optical band gap of 1.83 eV.