Palladium(II) complexes, oxime ligands, dimer, cyclic voltammetry, spectroelectrochemistry, electronic absorption spectra

In this work, Pd(L)Cl2] (L= pyridine oxime, pyrrole oxime and thiophene oxime) were prepared and their electrochemical behaviour and electronic absorption spectra were studied by cyclic voltammetry technique in DMF-(n-C4H9)4NBF4 solvent-electrolyte couple at room temperature vs Ag/AgCl reference electrode.Constant potential electrolysis of the palladium complexes were carried out at their first oxidation peak potentials and monitored by UV-Vis spectrophotometer. In order to suggest the reaction mechanism and to identify the final product of the electrochemical oxidation process of the complexes, the spectroelectrochemical studies were repeated at cold medium, as well. The obtained results were evaluated by correlating the results of mass spectrum, FTIR analyses and the chrono-coulometry measurements. It was found that palladium complexes yielded the dimer of the oximes with a two solvent coordinated palladium(II) chloride complexes via one electron transfer from a ligand based orbital during the electrochemical oxidation.