Synthesis and crystal structure of a copper(II) complex with 2,4-dihydroxybenzylidene benzoylhydrazone ligand

A new copper(II) complex with formula CuL(py), where L2- is the dianion of 2,4-dihydroxybenzylidene benzoylhydrazone, has been synthesized and characterized by IR spectra and single-crystal X-ray diffraction method. The crystal belongs to monoclinic, space group P2(1)/c with a = 0.9630(4), b = 1.4808(6), c = 1.2320(5) nm, beta = 104.969(6)degrees, V = 1.6973(11) nm(3), Z = 4, D-c = 1.553 g/cm(3), mu(MoK alpha) = 1.311 mm(-1), F(000) 812, R = 0.0694 and wR = 0.1727 for 1511 observed reflections (I > 2 sigma(I)). The crystal structure analysis indicates that the copper(II) ion lies in a distorted square-planar environment composed of two oxygen atoms, one nitrogen atom from the tridentate acylhydrazone Schiff base ligand L2- and one nitrogen atom from the pyridine ligand. Two adjacent molecules are connected via weak Cu center dot center dot center dot O bonding interactions to form dimers, which are further linked to generate a two-dimensional layer structure via interdimeric hydrogen bonds.