Theoretical studies of structural, optic and electronic properties of polypyrrole (PPy) oligomer

The paper demonstrates theoretical studies of structural, optical and electronic properties of polypyrroll oligomer.  first-principles calculations are used to investigate the electronic properties of n-pyrrole oligomers with n = 1–29, and all results were plotted to determine the optimal number of chains (n). Then, t ransition energies and oscillator strengths for the electronic excitation of the first 12 singlet-to-singlet excited states of PPy were calculated using time-dependent (TD) DFT at the same level. In addition, optical properties of PPy were studied as theoretically. It was observed that there is quite compatibility between the calculated and experimental data. We think that this systematic study may be useful for the structural analysis, spectroscopic and theoretical properties of other oxime I  think that this systematic study may be useful for the structural analysis, optical and theoretical properties of other polymers . .