Polythiophene as a sensor model for chlorofluorocarbon, fluorine, and oxygen gas using DFT calculations

Adsorption of CCl₃F, CCl₂F₂, CClF₃, F₂, and O₂ has been investigated systematically on the polythiophene (PT) moieties using density functional theory (DFT) calculations at the B3LYP/6-31G (d) level. Here, geometry optimizations have been performed on some polythiophene (5PT and 7PT) complexes. Likewise, adsorption energies, dipole moments, HOMO-LUMO orbital analysis, density of states (DOSs), global indices, and UV-vis spectra are calculated using the DFT method. Energies of interaction and HOMO-LUMO gap show that polythiophene has the highest sensitivity toward O₂ for B3LYP functional. According to our findings, CFCs, F₂, and O₂ molecules can be physically adsorbed on the moieties of polythiophene.