Study of copper(II) complexes of two diacetyl monooxime thiosemicarbazones: X-ray crystal structure and magneto-structural correlation of [Cu(dmoTSCH)Cl]2·H2O (dmoTSCH = monoanion of diacetyl monooxime thiosemicarbazone)

Abstract

Cu(II) complexes of the tridentate thiosemicarbazone ligands diacetyl monooxime thiosemicarbazone (dmoTSCH2) and diacetyl monooxime (4-phenyl)thiosemicarbazone (dmoPhTSCH2) have been synthesized. X-ray crystal structures of dmoPhTSCH2 and [Cu(dmoTSCH)Cl]2·H2O (1·H2O) are also reported. The Cu(II) compound 1·H2O is a dinuclear complex, where the Cu(II) centers have a square pyramidal geometry and are bridged by two thiolato ligands. A C2 axis passes through the middle of Cu2S2 rectangle. Variable temperature susceptibility measurement for 1·H2O shows that this compound exhibits a very weak antiferromagnetic behavior (in the solid state) with J1=−2.97cm−1, using the Heisenberg isotropic spin Hamiltonian (H=−J1S1·S2). DFT calculations show that the intramolecular magnetic interaction should be ferromagnetic, and the net antiferromagnetic behavior is due to competition with antiferromagnetic intermolecular interactions through hydrogen bonds.