Molecular modeling of the electronic properties and structure of polyaniline molecules

Polyaniline (PANI) is one of the most studied conducting polymers. Intense theoretical investigations during the past few years aim at explaining the chain organization, conductivity mechanism, and other structural and spectral characteristics. The present computational study sheds light on the molecular organization of a number of conformation model PANI. The calculations have been performedwith the semi-empirical method РМ7 using program МОРАС2016.The results of the theoretical calculations have been shown in this work. These are standard heats of formation ( ∆ f H 0 ), ionization potential (I X ), energy of higher occupied molecular orbital (E HOMO ) and a lower unoccupied molecular orbital (E LUMO ), dipole moments (D), volume (V) and area (S) of calculated molecules.The calculated numerical values of the heat of formation, dipole moments and ionization potentials are well in line with the experimental data. The values of E HOMO and E LUMO indicate the reduction nature of the PANI macromolecules. Growth on one link in a macromolecule leads to a decrease in the energy of ionization of polyaniline. It has been found that, depending on the value of the torsion angle, PANI molecules can form different conformations of the structures of macromolecules (compressed spiral, rod, expanded spiral).The calculated partial charges on the nitrogen atoms in macromolecules of polyaniline indicate a significant polarization of bonds, which may indicate the possibility of strong intermolecular interactions. Conformational analyses of oligomers were performed. K е yword : polyaniline, quantum-chemical calculations, heat of formation, conformational analysis.