Synthesis and characterization of a mononuclear and a dinuclear complex of CuIIwith (E)-2-((pyridine-2-yl)methyleneamino)benzenethiol ligand

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 Cu^II 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 Cu^II 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 Cu^II-Cu^II ions. The synthesized L¹H ligand was bound with the Cu^II ion in a tridentate manner, with SNN donor sites. The EPR spectra of Cu^II complexes provide information of about the extent of the delocalization of the unpaired electrons, indicating d_x²–_y² ground state. The half-wave potential values for Cu^II/Cu^I 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.