Electro-oxidative polymerization of Schiff-base of 1,8-diaminonaphthaline and 3-acetylthiophene. I. Preparation and study the redox behaviour of the resulting polymer

A Schiff-base of 1,8-diaminonaphthaline and 3-acetylthiophene was prepared and characterized by thin layer chromatography (TlC), IR, H-1-NMR, C-13-NMR and MS spectra. The electropolymerization of the resulting Schiff-base (I) namely 1-(methyl thiophenylidine)-8-naphthylamine (MTNA) on platinum and glassy carbon elect rodes in DMF/ACN solution containing 0.1 M LiClO4 and 10(-3) M of the Schif f-base (MTNA) was carried out by sweeping potential between -0.5 and 1.4 V at scan rate of 0.1 Vs(-1). The prepared polymeric film has weak or poor re dox response in non-aqueous and aqueous electrolytic solutions, but after i mmersing the polymeric film in 5 mM Ni(NO3)(2)/CH3CN for about 24 h, the re sulting loaded polymer was tested in CH3CN/LiClO4 and 0.1 M H2SO4 A well de fined redox response was obtained in both solutions and exhibit a thin laye r behaviour. The loaded poly-MTNA modified electrode behaved as an electroc atalyst for the electrode reaction of hydroquinone and catecol. The electro des are stable chemically and electro-chemically both in aqueous solutions and in mixtures containing methanol, making them excellent candidates for s ensing and/or electrocatalylic applications. (C) 2000 Elsevier Science Ltd. All rights reserved.