Department of Chemistry, National Institute of Technology, Patna-800 005, Bihar, India E-mail : mukesh@nitp.ac.in Department of Chemistry, Govt. V. P.G. College, Maihar-485 771, Madhya Pradesh, India Department of Chemistry, Govt. S. G. S. P.G. College, Sidhi-486 661, Madhya Pradesh, India Department of Chemistry, Govt. P.G. College, Seoni-480 661, Madhya Pradesh, India Manuscript received online 03 September 2014, revised 03 November 2014, accepted 13 November 2014 Mononuclear CuII complex, [Cu(L1 )(H2O)Cl] 1 and dinuclear complex [Cu2 (L1 )2 (Cl)2 ] 2, derived from (E)- 2-((pyridine-2-yl)methyleneamino)benzenethiol (L1H), was synthesized and characterized by various physico-chemical and spectroscopic techniques. IR spectra, electronic spectra and EPR spectroscopy of the complex 1 suggested a square pyramidal geometry around CuII ion. The two copper ions were penta-coordinated with distorted square pyramidal geometries for 2. The magnetic measurements of di-copper complex 2 exhibited the presence of antiferromagnetic exchange interaction between CuII-CuII ions. The synthesized L1H ligand was bound with the CuII ion in a tridentate manner, with SNN donor sites. The EPR spectra of CuII complexes provide information of about the extent of the delocalization of the unpaired electrons, indicating dx2–y2 ground state. The half-wave potential values for CuII/CuI redox couple obtained in aqueous solution as well as the reaction of the copper complexes with molecular oxygen and superoxide (O2 – ) radical elongated in DMSO are in agreement with the SOD-like activity of the copper(II) complexes.