Synthesis, X-ray structure and biological activity of mono- and dinuclear copper complexes derived from N-{2-[(2-diethylamino(alkyl)imino)-methyl]-phenyl}-4-methyl-benzenesulfonamide

[Display omitted] •Cu(II) complexes of N-{2-[(2-diethylaminoalkylimino)methyl]phenyl}-4-tosylsulfonamide were obtained.•Copper ions have either a distorted square planar or square pyramidal environment.•The obtained copper complexes exhibit high protistocidal activity. A series of copper(II) complexes with new Schiff bases, namely N-{2-[(2-diethylamino(alkyl)imino)-methyl]-phenyl}-4-methylbenzenesulfonamide [alkyl = ethyl (HL1) or propyl (HL2)], were synthesized using copper acetate or chloride and characterized by elemental analysis, IR and X-ray absorption spectroscopy, and single-crystal X-ray diffraction. The coordination geometry around the Cu(II) ion in Cu(L1)2 and Cu(L2)2 was studied by X-ray absorption spectroscopy. The crystal structures of copper(II) complexes with L1 ligand synthesized from copper chloride and copper acetate with addition of sodium azide have been determined by X-ray diffraction. The azomethines and all copper(II) complexes have been screened for their antibacterial, protistocidal, and fungistatic activities against Penicillium italicum, Colpoda steinii, Escherichia coli 078, and Staphylococcus aureus P-209.