Cobalt oxidative electropolymerization

Electrochromic polymer films have been prepared by oxidative electropolymerization of the monomer tetrakis(2-hydroxyphenoxy)phthalocyaninato cobalt(II) (43). The technique involved voltammetric cycling at 100 mV s from —0.2 to -1-1.2 V vs SCE in dry acetonitrile, resulting in the formation of a fine green polymer. Cyclic voltammograms during pol5mier growth showed the irreversible... 

Griveau, S., J. Pavez, J.H. Zagal, and E. Bedioui (2001). Electro-oxidation of 2-mercaptoethanol on adsorbed monomeric and electropolymerized cobalt tetra-aminophthalocyanine films Effect of film thickness. J. Electroanal. Chem. 497, 75-83. 

Griveau, S. and F. Bedioui (2001). Electrocatalytic oxidation of 2-mercaptoethanol by electropolymerized cobalt porphyrin film on vitreous carbon electrodes. Electroanalysis 13(3), 253-256. 

Yang et al. [49] developed eflicient molecular imprinted polymer (MIP) recognition elements for an electrochemical sensor by electropolymerizing the monomer of o-phenylenediamine (oPD), to form poly(o-phenylenediamine (PoPD)-film, Fig. 15, in the presence of template quinoxaline-2-carboxylic acid (QCA). Poly(pyrrole)-graphene oxide-binuclear phthalocyanine cobalt(ll) sulphonate (PPY-GO-BiCoPc) functional composite was achieved by controllable one-step electrochemical modification of GCE [49]. 

The authors have also reported on the comparison between the electrocatalytic activity of electropolymerized films of cobalt porphyrins and phthalocyanines (cobalt tetrakis(p-hydroxyphenyl)porphyrin cobalt tetrakis(o-aminophenyl)porphyrin and Co(II)-2), with emphasis on the effect of the film thickness on the electro-oxidation of 2-mercaptoethanol [52]. It was shown that, despite the porphyrins modified electrodes exhibit electrocatalytic activity, their activity strongly depends on the film thickness with a decrease of activity as the thickness increases, in contrast to the phthalocyanine-based electrodes. This difference in behavior was attributed to lower electronic conductivity of electropolymerized porphyrin films relative to phthalocyanine-based ones, and to the potential implication of the less reactive Co(III) form of the deposited porphyrin complexes. 

Griveau S, Gulppi M, Bedioui F, Zagal JH (2004) Electropolymerized cobalt macro complex-based films for thiols electro-oxidation effect of the film formation conditions and the nature of the macrocyclic ligand. Solid State Ion 169 59-63... 

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