Hydrothermal preparation, crystal structure, photoluminescence and UV-visible diffuse reflectance spectroscopic properties of a novel mononuclear zinc complex

Abstract

A novel mononuclear zinc complex [ZnL(Phen)(H2O)] · H2O containing the mixed ligands of Phen (Phen = 1,10-phenanthroline) and 3-hydroxy-2-methylquinoline-4-carboxylic acid (HL) was prepared by hydrothermal synthesis and its crystal structure was characterized by X-ray single-crystal diffraction method. The title complex crystallizes in the orthorhombic systems and forms monomeric units. The molecules in the title complex are connected through the interactions of hydrogen-bonding and p···p interactions to give a three-dimensional (3D) supramolecular structure. The fluorescence result discovers a wide emission band in the violet blue region. 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 shows there is a wide optical band gap.