ELECTROCHEMICAL-BEHAVIOR OF -METHYL-N'-(3-INDOL-1-YL-PROPYL)-4,4'-BIPYRIDINIUM - ANODIC POLYMERIZATION AND REDOX PROPERTIES OF THE VIOLOGENUNIT OF MONOMER AND POLYMER FILM

This article describes the synthesis and the electrochemical propertie s of a redox polymer, having a polyindole backbone and a viologen subu nit, derived from the oxidative electropolymerization of -methyl-N'-(3 -indol-1-yl-propyl)-4,4'-bipyridinium (In-V-Me2+). Fairly stable films of poly(In-V-Me2+) were obtained on Pt and Au electrodes from acetoni trile containing Et4NClO4 as supporting electrolyte. The best films we re grown on Au at potentials where electrodissolution of Au substrate occurs simultaneously with the electropolymerization. Poly(In-V-Me2+) films show interesting electrochemical properties in acetonitrile and water which stem from the behaviour of the pendant viologen redox cent res. The redox reactions of the monomer have also been studied. The in dole viologen shows the usual behaviour of viologen compounds both in aqueous solutions and in acetonitrile. In aqueous solutions, In-V-Me2 forms on mercury monolayers of radical cations deposited at underpote ntials with parallel and vertical orientation on the electrode surface . (C) 1998 Elsevier Science Ltd. All rights reserved.