Evolution of the electronic states of polyaniline: an ab initio analysis of the orbital states of PAni synthons

In this work, ab initio computations performed using the B3LYP hybrid densi ty functional are applied to describe the full electronic character of poly aniline (PAni) in terms of its logical structural subunits and/or its synth ons. A complete description of bonding, redox states, and spectroscopic ter ms is obtained from this analysis, suggesting that structural and electroni c properties of PAni are attributable to its synthons; aniline, p-phenylene diamine, and N,N'-bis(4'-aminophenyl)-1,4-quinonediimine Though previous m odeling attempts with semi-empirical or simple Hartree-Fock methods have pr ovided useful qualitative data, the ab initio/DFT approach used here has be en shown to be quantitatively accurate. The general approach to understandi ng properties of complex materials in terms of its smaller structural units and synthons will be generally useful for polymers and complex clusters. ( C) 1999 Published by Elsevier Science S.A. All rights reserved.