A new functionalized conductive polymer poly2-methyl-5-amino-1,4-naphthoquinone) PMANQ) with two distinct redox systems S. Hubert a,b , M.C. Pham a,* ,LeH.Dao b , B. Piro a , Q.A. Nguyen c , M. Hedayatullah a a ITODYS, Universite  Paris 7-Denis Diderot, UMR CNRS 7086, 1 rue Guy de la Brosse, 75005 Paris, France b Laboratoire de Recherche sur les Mate Âriaux Avance Âs, INRSÐEnergie et Mate Âriaux, 1650 Bd Lionel Boulet, Varennes, Que Âbec, Canada J3X 1S2 c Institut de Chimie, CNST, Hanoi, Viet Nam Received 12 July 2001; received in revised form 12 November 2001; accepted 25 November 2001 Abstract Theelectrooxidationof2-methyl-5-amino-1,4-naphthoquinoneMANQ)onplatinumorglassycarbonGC)electrodesinacetonitrileleads to poly2-methyl-5-amino-1,4-naphthoquinone) PMANQ) ®lms. Films were characterized by UV±VIS, X-ray photoelectron spectroscopy XPS), ex situ FT-IR and in situ multiple internal re¯ection FT-IR spectroscopies MIRFT-IRS). Results converge to a de®nition of the polymerstructure,whichisofthepolyanilinetype,bearingonemethylquinonegrouppermonomerunit.Theelectrochemicalpropertiesof PMANQ®lminorganicandaqueousmediawerestudiedbyMIRFT-IRSandinsitud.c.conductivity.The®lmisconductinginnegativeas well as in positive potential range. # 2002 Elsevier Science B.V. All rights reserved. Keywords: Conducting polymer; In situ infrared spectroscopy; In situ conductivity 1. Introduction AnewtypeofECPhasbeendevelopedinourlaboratory, by electrooxidation of functionalized aminonaphthalene derivatives [1,2]. Recently, we developed a polyamino- naphthoquinone®lmPANQ)withcation-exchangeproper- ties[3,4].Thequinone®lmshavealreadybeenstudiedinthe literature [5±12], but it was the ®rst time that the quinone group was electrochemically stable and completely electro- active within a polymer ®lm. PANQ was an interesting electrode material for lithium batteries [13]. Unfortunately, for PANQ, the redox process related to the p-conjugated system p-doping) is not quite stable. In order to improve the electrochemical performance of the system, a new substituted monomer was considered: 2- methyl-5-amino-1,4-naphthoquinoneMANQ),whichisthe subjectofthispaper.Themonomersynthesiswasdeveloped and achieved in the laboratory and poly2-methyl-5-amino- 1,4-naphthoquinone)PMANQ)®lmwaselectrochemically grown. We emphasize on the originality of PMANQ which presents two redox processes concerning two distinct sys- tems, the quinone group and the p-conjugated system. This could be interesting for potential applications in energy storage, in the same manner than with n- and p-dopable polythiophene derivatives [14±16]. Electrosynthesiswasimplementedbycyclicvoltammetry and the ®lms were characterized by UV±VIS, X-ray photo- electron spectroscopy XPS), ex situ FT-IR and in situ multipleinternalre¯ectionFT-IRMIRFT-IRS)spectrosco- pies. A theoretical approach was used to con®rm the mole- cular structure of the polymer. Results converge to a de®nition of the structure, which is of the polyaniline type, bearing one methylquinone group per monomer unit. PMANQ ®lm is electroactive in organic medium, but also in organic and aqueous acid. The redox mechanisms of the ®lm were studied by in situ MIRFT-IRS and conductivity measurements. 2. Experimental All electrolytes and synthesis solutions were prepared with reagent quality chemicals. Synthetic Metals 128 2002) 67±81 * Correspondingauthor.Tel.: 33-1-4427-6961; fax: 33-1-4427-6814. E-mail address: mcpham@paris7.jussieu.fr M.C. Pham). 0379-6779/02/$ ± see front matter # 2002 Elsevier Science B.V. All rights reserved. PII:S0379-677901)00653-1