Molecular modeling analyses of polyaniline substituted with alkali and alkaline earth elements

Document Type

Article

Publication Date

Winter 12-2018

Abstract

Polyaniline which is termed as PANi is chosen as model molecule where substitution with Li, Na, K, Be, Mg and Ca is carried out. Each metal is supposed to interact with PANi throughout the amide group at the terminal and then in the middle of PANi. Quantum mechanical calculations at B3LYP/6-31G (d,p) level are conducted for PANi as well as substituted PANi. Bond distances, bond angles, total dipole moment (TDM), frontier band gap energy (HOMO/LUMO) as well as molecular electrostatic potential (ESP) are calculated. Results indicate that for terminal amide group interaction, PANi-Na has the highest TDM (10.5996 Debye) and the lowest HOMO/LUMO band gap energy (2.0169 eV). Also for PANi-Ca, TDM (6.4356 Debye); HOMO/LUMO (1.1970 eV). For the interaction through the middle NH group, PANi-K and PANi-Mg are the more active sites for interaction as they have the highest TDM, having the values of 11.5939 and 3.1208 Debye respectively, and the lowest HOMO/LUMO band gap energies of 1.6732 and 1.3168 eV respectively. ESP drives a general conclusion that the electronegativity of PANi increases significantly by the presence of alkali metals and increases slightly by the presence of alkaline earth metals. Additionally, there are changes in the geometrical parameters (including both bond lengths and bond angles) for all studied model molecules.

Share

COinS