Novel multinuclear transition metal(II) complexes based on an asymmetric Salamo-type ligand: Syntheses, structure characterizations and fluorescent properties

Abstract

Three multinuclear complexes, [{Cu(HL)(OAc)Cu}2]·CH3OH, [Zn(HL)(OAc)Zn(CH3CH2OH)] and [{Cd(HL)(OAc)Cd(CH3CH2OH)}2]·2CHCl3, have been synthesized with an asymmetric Salamo-type ligand H4L, and characterized by FT-IR, UV–vis spectra and X-ray crystallography. The Cu(II) complex contains two crystallographically independent but chemically identical dinuclear complexes (molecules 1 and 2). Meanwhile, self-assembled infinite 1D, 2D and 3D structures are formed by intermolecular hydrogen bonds and C–H⋯π interactions of neighboring complexes in the solid state. The Zn(II) complex also forms a novel dinuclear structure. And a self-assembled infinite 2D structure is formed by C–H⋯π interaction of neighboring complexes in the solid state. Otherwise, the Cd(II) complex forms an infinite 1D structure by C–H⋯π interaction of the neighboring complex molecules. In addition, the photophysical properties of the Cu(II), Zn(II) and Cd(II) complexes have also been discussed.