Various poly(o-phenylenediamine) derivatives (e.g. poly(2,3-diaminotoluene) (PDT) and poly(N-n-butyl-o-phenylenediamine) (PBPD)) have been prepared electrochemically and characterized. Cyclic voltammetry measurements in different acidic conditions have revealed a one-step oxidation process in these polymers which implies the formation of deprotonated imines in PDT and of some oxidized (charged) substituted imines in PBPD. However, in-situ conductivity measurements showed that both materials have low electrical conductivities (with a maximum of 10(-4)-10(-3) S cm(-1)). On the basis of results obtained on model compounds (5,12-dihydro-5,7,12,14-tetraazapentacene and some derivatives), these low electrical conductivities can be explained by a low concentration of charge carriers and poor interchain contacts.