Theoretical investigation of the aluminum/polyaniline interface

We investigate theoretically the structure and electronic properties of the interface between aluminum and polyaniline in order to obtain information on the most favored adsorption sites and the nature of the interactions occurring between the metal and the polymer surface. For this purpose, quantum chemical calculations are performed on model systems consisting of short-chain model molecules interacting with two metal atoms. We use both an ab initio Hartree-Fock Hamiltonian with an extended basis set and the MNDO semiempirical technique to study the complex between two Al atoms and p-phenylenediamine, a model molecule for leucoemeraldine base. The formation of stable complexes between two Al atoms and the molecules induce strong geometric modifications along the organic backbone: electron charge transfer takes place from the metal atom to the organic system and the π electronic levels are strongly perturbed.