Synthesis of Copper complexes of a new symmetrical dihydrazone: Characterization, XRD studies, DFT calculations and biological activity

A novel series of binuclear Cu(II) chelates of 2,2'-thiobis(N-benzylidene)acetohydrazide) (H2L) obtained by the condensation of 2,2'-thiodi(acetohydrazide) with benzaldehyde was synthesized using different copper salts. The prepared copper complexes were identified by elemental analysis, spectral (IR, UV-visible, ESR, 1H, 13CNMR and mass), as well as magnetic and thermal measurements. The ligand behaves either as mono- or dibasic NNOOtetradentate. The formulae:[Cu2(L-H)(OH)2(C2H5O)(H2O)], [Cu2(L-2H)(L-H)(OAC)(H2O)].4H2O, [Cu2(LH) 2(NO3)2].2H2O and [Cu2(L-2H)SO4(H2O)3]H2O.1/2C2H5OH were suggested for the newly synthesized complexes.On the premise of their electronic spectra and magnetic moments data; square planner, square pyramidal and octahedral geometries were proposed for the complexes. Details of the chemical constitution of the [Cu2(L- H)(OH)2(C2H5O)(H2O)]complex were obtained from X-ray powder diffraction data. The geometries of all investigated compounds were further affirmed by DFT calculations. Moreover, the synthesized compounds were examined for their antibacterial and superoxide dismutase (SOD)-like activities.