Optical and EPR studies of LiCl pseudodoping of emeraldine base

Abstract

Similar to the doping of the emeraldine base (EB) form of polyaniline with protonic acids, we report the pseudodoping of EB with Li+ ions. This assignment of Li+ doping is based upon the observation of defect states in the bandgap and associated spins for EB processed with LiCl. However, the signatures of the doped phase do not grow monotonically with increasing LiCl doping level, suggesting a unique equilibrium between the Li+ ion associating with the imine nitrogen of EB and possibly a LiCl cluster. Even at the maximal doping level, LiCl doped EB is not a metal but rather a strongly localized charged insulator.