Electropolymerization of non-substituted Mg(II) porphine: Effects of proton acceptor addition

Electropolymerization of unsubstituted magnesium porphine in acetonitrile solutions possessing various proton-accepting properties has been studied. The overall rate of the polymer-product accumulation on the electrode surface has been established to be limited by the deprotonation step of intermediate species. This conclusion is based on the observed influence of proton-accepting additives, water or 2,6-dimethylpyridine (lutidine), on the Mg-porphine electrooxidation process. Lutidine addition into the polymerization bath enables one to enhance strongly the rate of the film growth and the efficiency of this process increases more than by a factor of two, redox, electric conductivity and spectral properties of thus obtained polyporphine films remaining unchanged, while this non-coordinating agent, lutidine, is not included inside such films. Measurement of the electric resistance of magnesium polyporphine film obtained with lutidine addition has been carried out for its various redox states. Correlation between the redox and electron-conductive properties of the polyporphine film for various potential ranges has been observed. (C) 2014 Elsevier B.V. All rights reserved.