Tetranuclear Zn(II) Complex Based on an Asymmetrical Salamo-Type Chelating Ligand: Synthesis, Structural Characterization, and Fluorescence Property

A new tetranuclear Zn(II) complex, [{Zn(L)(μ-OAc)Zn(H 2 O)} 2 ], based on an asymmetrical salamo-type bisoxime chelating ligand H 3 L (6-hydroxy-4′-chloro-2,2′-[ethylenediyldioxybis(nitrilomethylidyne)]diphenol) was synthesized and characterized by elemental analyses, differential thermal methods, single-crystal X-ray crystallography, and IR, UV–vis, and fluorescence spectra. The Zn(II) complex crystallizes in the triclinic system, space group P -1 with cell parameters a = 9.0742(6) Å, b = 11.8225(5) Å, c = 12.4182(8) Å, Z = 2, V = 1212.56(12) Å 3 , R 1 = 0.0572, and wR 2 = 0.1734. The environment of the tetranuclear Zn(II) complex is penta-coordinated having a slightly distorted trigonal bipyramidal geometry. Moreover, a 1D chain supramolecular structure is formed along the c -axis by the intermolecular C1–H1B⋯O14 hydrogen bonds; in the same manner, C2–H2C⋯Cg2 functions in the formation of supramolecular structures along the a -axis of the 1D chain. A 2D supramolecular structure along the ac plane extends infinitely under the force of intermolecular hydrogen bonds. Differential scanning calorimetry-thermogravimetry thermal analysis provides evidence of the coordination of Zn(II) atoms to the ligand H 3 L. The Zn(II) complex shows intense photoluminescence with a maximum emission at ~453 nm upon excitation at 360 nm.