CHARGE-TRANSPORT AND ELECTRON LOCALIZATION IN POLYANILINE DERIVATIVES

Electrical conductivity, magnetic susceptibility, and electron-spin-resonance studies are reported in polyaniline and its derivatives poly(o-toluidine), poly(o-ethylaniline), and poly(o-propylaniline). It is shown that substituents on the C6 rings of the polymer backbone lead to decreased conductivity, decreased Pauli susceptibility, and an increased number of Curie spins. Also reflecting these features are electron-spin-resonance line shapes, which transform from Lorentzian for polyaniline toward Gaussian for poly(o-propylaniline). These results are interpreted in terms of increased electron localization caused by increased interchain disorder. Furthermore, evidence of electron-electron correlations is presented for poly(o-propylaniline).