Thin films of metal—dibenzotetraaza[14]annulene complexes—part 4. Mechanistic reinvestigations of the electropolymerization of Ni (II) and Cu (II) complexes at an electrode surface. Sequential electrochemical formation of dimers, oligomers and polymers

Abstract

The electrochemical behaviour and electropolymerization of Ni (II) and Cu (II) dibenzotetraaza[14]annulene complexes have been reinvestigated in detail in CH 3CN and CH 2Cl 2. It appears that the corresponding electroactive polymeric films can be obtained in protonated or unprotonated forms depending on the electrochemical procedure used. Electrochemical properties of the corresponding dimeric complexes of nickel (protonated or not) have been established. The protonated dimer is probably the key species involved in the polymerization process. Formation of oligomeric Ni-complexes can be obtained by sequential oxidation of the monomer. Electropolymerization of the Cu-complex appears less efficient than that of the Ni while the electroactivity of the resulting films is destroyed at anodic potentials above 1 V.