|Search for content and authors
Electrochemical polymerisation and electrocatalytic properties of structured selected aminophenyl derivatives of some metalloporphyrins
|Ievgen Obraztsov 1, Wlodzimierz Kutner 1, Channa A. Wijesinghe 2, Francis D'Souza 2
1. Polish Academy of Sciences, Institute of Physical Chemistry, Kasprzaka 44/52, Warszawa 01-224, Poland
Electrochemical polymerisation of zinc and cobalt metalloporphyrins bearing peripheral aminophenyl substituents, vis. tetrakis-N,N-diphenylaminophenyl-porphyrinazotozinc (diphenyl ZnTPP) and tetrakis-N,N-diphenylaminophenyl-porphyrinazotocobalt (diphenyl CoTPP) as well as N,N-diphenylaminophenyl-porphyrin (diphenyl TPP) in the 1,2-dichlorobenzene solutions of different tetraalkylammonium salt supporting electrolytes, was investigated by simultaneous multi-scan cyclic voltammetry (CV) and piezoelectric microgravimetry at an electrochemical quartz crystal microbalance using 10-MHz quartz crystal resonators with gold film electrodes. The electropolymerisation was investigated by simultaneous measurement of CV current, resonance frequency changes, and dynamic resistance changes as a function of potential scanned. Integrity of the resulting polymer films was confirmed ex situ by the reflection mode UV-vis spectroscopy and X-ray photoelectron spectroscopy measurements. The dependence of peak currents of the polymer films in the blank organic solvent supporting electrolyte solutions on the anion size indicated diffusional control of the film conductivity. Electrocatalytic properties of the polymers with respect to the dioxygen electroreduction were investigated. For that purpose, metalloporphyrin monomers were structured with cyclic amine bidentate ligands, such as pyrazine or piperazine, to form sandwich-type stacked complexes and, then, electropolymerised. These ligands served as structuring templates. Subsequently, the templates were extracted from the polymer with an acidic water solution. Then, electrocatalytic properties of the metalloporphyrin polymers in aerated aqueous solutions were examined by CV.
Presentation: Poster at SMCBS'2007 International Workshop, by Ievgen Obraztsov
See On-line Journal of SMCBS'2007 International Workshop
Submitted: 2007-10-16 19:52 Revised: 2009-06-07 00:44