Electrochemical investigations on copper(II) complexes with quardidentate Schiff bases with 0 2N2 donor set

Department of Chemistry, University of Allahabad, Allahabad-211 002, Uttar Pradesh, India E-mail : dr_krishna_s@yahoo.co.in Manuscript received 3 July 2007, accepted 6 July 2007 The electrochemical investigations of Cu(salcn), 1 and Cu(salophen), 2, where salcn = N,N' -ethylencbis-( salicylaldiminato) dianion and salophen = N ,N' -phenylenebis-(salicylaldiminato) dianion, have been carried out in dimethylformamide (DMF) containing 0.1 M sodium perchlorate (NaCIO4), 0.1 M tetrabutyl ammonium pechlorate (TBAP) and tetramethyl ammonium chloride (TMACI) as the supporting electrolyte using cyclic voltammetry at a platinum working electrode. Both these complexes show similar electrochemical behaviour under identical solution conditions. Complexes 1 and 2 revealed a diffusion- ontrolled, quasi-reversible one-electron transfer process (Cu2+/+) at a more negative potential with E0' = -1235 to -970 mV vs SCE, suggesting a greater redox stability of these complexes. It i found that the reduction potential of 2 is more positive than that of 1, indicating easier reduction of the former. It is also observed that the redox potentials of both these complexes are influenced by the nature of the supporting electrolyte