Computational Investigation Of Conducting Polythiophenes And Substituted Polythiophenes

Thiophene oligomers up to eight thiophene units and 3-(2,5-dialkoxyphenyl) thiophenesrnhave been investigated using HF/STO-3G, DFT/STO-3G, DFT/3-21G*, and DFT/6-rn31G* computational levels. The structures are optimized to calculate the thermodynamicrnproperties, UV-Vis absorption wavelength, and band gap of the oligomers. Increase in thernnumber of thiophene rings increases the stability of both the doped and undoped states.rnThe band gap decreases with increases in the number of thiophene rings. Up onrnoxidation, the band gap became further narrower compared with the neutral forms.rnIntroducing dialkoxy phenyl-substituent at the 3-position of thiophene enhanced thernstability and band gap of the oligomers. Longer alkoxy chains on the phenyl ring madernthe oligomers to be more stable and to have narrower band gap.rnKey words: Thiophenes, density functional theory, band gap, excitation energy, andrnthermodynamic properties

Get Full Work

Report copyright infringement or plagiarism