ELECTROCHEMISTRY OF POLY(VINYLFERROCENE) FORMED BY DIRECT ELECTROCHEMICAL REDUCTION AT A GLASSY-CARBON ELECTRODE

A thin him of poly(vinylferrocene) (PVF) is prepared by direct electro chemical reduction of vinylferrocene in acetonitrile at a glassy carbo n electrode using cyclic sweep voltammetry between +0.8 and -2.8 V (vs . Ag/AgCl). PVF films of varying surface coverages, up to a maximum of 2.2 x 10(-9) mol cm(-2) of ferrocene, can be obtained by controlling the number of sweep cycles. These films are highly stable and electroa ctive, possessing electrochemical characteristics which are strongly a ffected by the nature of counter ions in aqueous media. The concentrat ion of the ferrocenyl group at the polymer modified electrode is estim ated as 5.9 mol dm(-3), assuming a dry density of 1.25 g cm(-3) for th e polymers. These easily prepared, highly stable, redox-active thin fi lms effectively block the access of an osmium redox probe to the elect rode surface.