Analysis of X-ray photoelectron spectra of electrochemically prepared polyaniline by DFT calculations using model molecules

In order to clarify the electronic state of polyaniline synthesized electrochemically, we analyzed valence X-ray photoelectron spectra (XPS) and core-electron binding energies of N,N’-Diphenyl-1,4-phenylenediamine and polyaniline by deMon density-functional theory calculations (DFT) using the molecule and model molecule, respectively. Polyaniline has been synthesized electrochemically from two different thin films on platinum plates in oxidation and reduction states, respectively. Valence XPS of the conductive polymers were analyzed by deMon DFT calculations using model tetramers of the four chemical structural formulae (1S, 2S, 1A, and 2A) which MacDiarmid and co-workers proposed. We can conclude that the oxidized polyanililine corresponds to the 2A type, while the reduction form approximated the 1S type. (C) 2002 Elsevier Science B.V. All rights reserved.