Tuning pyrrole oligomers for optoelectronic and anti-corrosion applications: a DFT/TDDFT study

The determination of optoelectronic properties for 15 pyrrole oligomers tagged with different donor and acceptor groups and their potential anti-corrosion properties were considered. Density functional theory and time-dependent density functional theory (DFT/TDDFT) calculations have been utilized to explore the structure, molecular properties and anti-corrosion abilities of pyrrole oligomers. Frontier molecular orbital analysis gives qualitative information about the band gap and details of orientation of HOMOs and LUMOs on pi-bridge, donor and acceptor moiety. The hyperpolarizability (beta degrees) values are in good agreement with the calculated band gap. TDDFT calculation reveals the absorption maxima of pyrrole oligomers are in the UV-Visible region. The fraction of electron ( increment N) an essential factor for corrosion inhibition is calculated as per Lukovit study. On the whole, modelled pyrrole oligomers illustrate better inhibition property than the experimentally reported inhibitor and exhibit optoelectronic property.