Tetranuclear Copper(II) and Zinc(II) Complexes Constructed from an Asymmetrical Salamo-Type N2O3 Donor Ligand: Syntheses, Structures and Fluorescence Properties

Two newly designed tetranuclear complexes, (Cu(L)(OAc)Cu(H2O))(2) (1) and {Zn(L)(OAc)Zn(H2O)}(2) (2) derived from an Salamo-type N2O3 donor ligand (H3L) were synthesized and characterized by elemental analyses, IR and UV-Vis spectra, fluorescence spectra and X-ray crystallography. Complex 1 is made up of four Cu(II) ions, two deprotonated L3- moieties, two coordinated water molecules and two mu(2)-acetate ions. All of the Cu(II) ions in 1 are penta-coordinated with slightly distorted tetragonal pyramidal and trigonal bipyramidal symmetries. Complex 1 forms an infinite 1D chain supramolecular structure via C-H center dot center dot center dot pi interactions. Complex 2 reveals an asymmetrical tetranuclear structure, and consists of four Zn(II) ions, two completely deprotonated L3- units, two mu(2)-acetate ions and two coordinated water molecules, which possesses an infinite 3D supramolecular structure. The fluorescent properties of H3L and complexes 1 and 2 have also been discussed. CCDC: 1484596, 1; 1484597, 2.