Crystal structures and photophysical properties of mono- and dinuclear Zn complexes flanked by tri-ethyl-ammonium.

Two new zinc(II) complexes, tri-ethyl-ammonium di-chlorido-[2-(4-nitro-phen-yl)-4-phenyl-quinolin-8-olato]zinc(II), (CHN){Zn(CHNO)Cl] (), and bis-(tri-ethyl-ammonium) {2,2'-[1,4-phenyl-enebis(nitrilo-methyl-idyne)]diphenolato}bis-[di-chlorido-zinc(II)], (CHN)[Zn(CHNO)Cl] (), were synthesized and their structures were determined using ESI-MS spectrometry, H NMR spectroscopy, and single-crystal X-ray diffraction. The results showed that the ligands 2-(4-nitro-phen-yl)-4-phenyl-quinolin-8-ol () and ,'-bis-(2-hy-droxy-benzyl-idene)benzene-1,4-di-amine () were deprotonated by tri-ethyl-amine, forming the counter-ion EtNH, which inter-acts an N-H⋯O hydrogen bond with the ligand. The Zn atoms have a distorted trigonal-pyramidal () and distorted tetra-hedral () geometries with a coord-ination number of four, coordinating with the ligands N and O atoms. The N atoms coordinating with Zn correspond to the heterocyclic nitro-gen for the ligand, while for the ligand, it is the nitro-gen of the imine (CH=N). The crystal packing of is characterized by C-H⋯π inter-actions, while that of by C-H⋯Cl inter-actions. The emission spectra showed that complex exhibits green fluorescence in the solid state with a small band-gap energy, and the complex does exhibit non-fluorescence.