Copper complexes derived from 1-(2-carboxybenzoyl)thiosemicarbazide (H 3L): syntheses, characterization and crystal structure of [Cu 3L 2(Py) 6](HIm)(H 2O) 2

Abstract

The reaction of CuCl 2·2H 2O with 1-(2-carboxybenzoyl)thiosemicarbazide (H 3L) and imidazole (HIm) in NaOH gave a Cu II complex, which was crystallized from pyridine (Py) to give complex 1, [Cu 3L 2(Py) 6(HIm)](H 2O) 2. The complex molecule contains a linear Cu 3 array in which the central copper atom at the crystallographic inversion centre has an octahedral environment and the other two Cu atoms are square pyramidal, each bridged to the central Cu atom via the L group, with the atoms O(1) and N(2) chelating to Cu(1), and the atoms N(1), S and O(2) to Cu(2). The carboxylate groups coordinate to the metal atoms in a unidentate fashion. Complex 2, [Cu 2(H 3L) 2Cl 2](H 2O) 3, obtained by the reaction of CuCl 2·2H 2O with H 3L has been characterized by IR, UV, NMR ( 1H and 13C) spectra, and TGA and molar conductance measurements. The ESR and magnetic moment measurements show that the Cu atoms in complex 2 are in the Cu 1 oxidation state.