Surface-modified Electrodes: Oxidative Electropolymerisation of Macrocyclic Complexes of Fe(III) and Ni(II)

Me2-dibenzo[b,k]-dipyridyl[f,o][1,4,7,10,13,16]-hexaaza-5,9,14,19-tetraoxo-cyclooctadecane macrocyclic complexes of Fe(III) and Ni(II) have been synthesized by template method and analysed with various techniques like molar conductance, FT-IR, UV-Vis, Mass spectra. The studies of surface-modified electrode based on tThe oxidative electropolymerisation of the monomeric Fe[Me2-(DBDPy)N6tetraoxo[18]Cl2]Cl and Ni[Me2-(DBDPy)N6tetraoxo[18]Cl2] complexes were carried out on the Pt electrode in DMSO containing 0.1 M TEAP, by employing cyclic voltammetry. A thin film of polymer, [M-Me2-(DBDPy)N6tetraoxo[18]Cl2]n , where M=Fe(III) and Ni(II), was formed on the electrode surface by constant potential electrolysis at 1.5 V on cycling from -1.5 to +2.0 V vs Ag/AgCl.The monomers, after polymerization form [M-Me2-(DBDPy)N6tetraoxo[18]Cl2]n , where M=Fe(III) and Ni(II), which form a thin film on the electrode surface. The film formed on the electrode surface by constant potential electrolysis at 1.5 V on cycling from -1.5 to +2.0 V vs Ag/AgCl The magnitude of film growth depends on the method of deposition in the solvent and the rate of cycling i.e 10 cycles from -1.5 to +2.0 V vs Ag/AgCl at 200 mVs-1 scan rate resulted in “Polymer layers” formation on Pt electrode. Film growth was also dependent on the concentration of the electrolyte and the electrode surface and found that the heterogeneous electron transfer rate constant is increased with the growth of the film. UV-Visible and FT-IR spectra suggest that the macrocycles remained in the polymeric film.