Electrocopolymerization of (1-chloro-2-formylvinyl) ferrocene and vinylpyridine complex of ruthenium

(1-Chloro-2-formylvinyl)ferrocene (2) and [Ru(bpy)(vpy)2] (PF6)2 (1) (bpy = 2,2′-bipyridine, vpy = 4-vinylpyridine) were copolymerized through reductive electropolymerization in acetonitrile containing 0.1 mol·L-1TBAH as supporting electrolyte. The electropolymerization was conducted by cyclic voltammetry from 0.7 to -2.15 V vs. Ag+/Ag, using glassy carbon as the working electrode and platinum wire as counter electrode. After thoroughly rinsed by acetone and acetonitrile, the resulting film demonstrated two pairs of redox peak when cyclic voltammetry scanned in the monomer free electrolyte solution, corresponding to Fc+/Fc (0.16 V vs. Ag+/Ag) and Ru3+/Ru2+(0.93 V vs. Ag+YAg) couples respectively. Surface coverage of electroactive sites, based on Fc+/Fc couple, was 1 × 10-8mol·cm-2, the same as the single polymer of 2 made through more than 79 times scan. The polymerization of 2 was enhanced by copolymerization with 1 since the copolymer with a 1 × 10-2mol·cm surface coverage of electroactive ferrocene sites was made by only 10 times scan. This is also proved by the much stronger redox peak currents of Fc+/Fc couple in copolymer compared with those in homopolymer of 2 made under the similar conditions. Electrooxidations of 4-methoxylphenol and catechol in aqueous NaOAc solution catalyzed by the copolymer demonstrated much stronger oxidation current of the phenol at this electrode compared with those at GC. Cyclic votammetry of o-nitrobenzene at electrode coated with the copolymer was very different from that at GC. The reoxidation of reduced o-nitrobenzene shifted positively to the potential of Fc+/Fc couple, indicating that the reoxidation was mediated by the oxidation of electroactive ferrocene sites in the polymer.