Raman spectroelectrochemical studies of copolymers of o-phenylenediamine and o-toluidine

Conducting homo- and copolymers of o-phenylenediamine (OPD) and o-toluidine (OT) were studied with in situ Raman spectroelectrochemical measurements using red laser illumination (647.1 nm) within a broad electrochemical potential window ranging from ESCE = −0.2 to 0.6 V. Experimental results show that the spectroelectrochemical characteristics of the polymers synthesized from mixed OT and OPD solution, particularly at lower OPD feed concentration, are considerably different from those of the corresponding homopolymers, suggesting formation of a copolymer during the electrolysis of mixed solutions of OPD and OT. Specific Raman features of the homo-/copolymers have been identified. The effects of polymerization conditions with respect to OPD feed concentration on the Raman intensity of various bands of the polymers are discussed. The influence of applied electrode potential on the Raman intensity of various bands is demonstrated.