Density functional theory studies of polypyrrole and polypyrrole derivatives; substituent effect on the optical and electronic properties

Abstract

Electronic and vibrational structures of pyrrole oligomer and its derivatives were established on the basis of Density Functional Theory (DFT) and Time-dependent DFT (TD-DFT) computations. The influence of substituent groups on optical and electronic properties was investigated for polypyrrole and polypyrrole derivatives. Molecular structure and frontier molecular orbitals of neutral and ionized oligomers were analyzed. The energy gap, ionization potential, electron affinity, electronegativity, and hardness were calculated and discussed.