FTIR spectroscopic investigations of polyaniline derivatives± palladium systems M. Hasik a , A. Drelinkiewicz b , E. Wenda b , C. Paluszkiewicz a,c, * , S. Quillard d a Department of Materials Science and Ceramics, University of Mining and Metallurgy, Al. Mickiewicza 30, 30-059 Krako Âw, Poland b Department of Chemistry, Jagiellonian University, ul. Ingardena 3, 30-060 Krako Âw, Poland c Regional Laboratory of Physicochemical Analysis and Research, Jagiellonian University, ul. Ingardena 3, 30-060 Krako Âw, Poland d Institut des Materiaux, rue de la Houssiniere, 44072 Nantes Cedex 03, France Received 9 November 2000; revised 16 February 2001; accepted 16 February 2001 Abstract Ring-substituted polyaniline derivatives: polyo-toluidine) POT) and polyo-chloroaniline) POC) have been treated with PdCl 2 solutions in 0.1 and 1 M HCl. Polymer±palladium systems thus obtained have been studied by vibrational spectroscopic methods MIR, FIR, Raman) and chemical analysis. Results have been compared with those obtained for unsubstituted polyaniline PANI)±palladium systems prepared under similar experimental conditions as well as for POT, POC, PANI treated with 0.1 and 1 M HCl. It has been found that in all the cases polymers are protonated. Substitution of one hydrogen atom in PANI ring with ±Cl and ±CH 3 in¯uences the basic and redox properties of the parent polymer The lowest reactivity towards palladium ions has been observed in the case of POC. q 2001 Elsevier Science B.V. All rights reserved. Keywords: Polyaniline; Polyaniline derivatives; Polyo-toluidine); Polyo-chloroaniline); Palladium 1. Introduction During 20 years of studies of conjugated poly- mers, more than 8000 papers have been published on polyaniline PANI). Much less scienti®c effort has been devoted to PANI derivatives. The present work deals with two PANI derivatves, i.e. polyo- toluidine) POT) and polyo-chloroaniline) POC) in which one hydrogen atom of the parent polymer rings has been substituted with chlorine POC) or methyl group POT), exhibiting different electronic effects. PANI, POT and POC can exist in various oxidation states which can be mutually intercon- verted in appropriate conditions. Thus, three main forms of PANI, POT and POC, i.e. fully reduced leucoemeraldine I), half-oxidized emeraldine II) and fully oxidized pernigraniline III) can be obtained as shown below. It should be pointed out that the oxidation level of PANI and its derivatives can change continuously, i.e. various intermediate forms between the main ones Journal of Molecular Structure 596 2001) 89±99 0022-2860/01/$ - see front matter q 2001 Elsevier Science B.V. All rights reserved. PII: S0022-286001)00694-9 www.elsevier.com/locate/molstruc * Corresponding author. Address: Regional Laboratory of Physi- cochemical Analysis and Research, Jagiellonian University, ul. Ingardena 3, 30-060, Cracow, Poland. Tel.: 148-12-172487; fax: 148-12-343859. E-mail address: ucpalusz@cyf-kr.edu.pl C. Paluszkiewicz).