Theoretical study of fluorinated phenylthiophenes as candidate materials for charge-storage applications

•Fluorine substitution plays a fine-tune effect on the structure-energetics of FPTs.•B3LYP/6-311G(d,p) level of theory was employed on the neutral and ionic species.•Electronic indexes correlated linearly with the Hammet function.•Doped states had more suitable properties reflecting charge transport effects.•Result obtained can be extended to conducting oligo- and poly(FPT) species.

A series of fluorine-substituted phenylthiophenes (FPTs) were studied by means of the density functional theory (DFT). The structural, electronic, and energetic properties of the titled molecules were discussed and rationalized in term of the number and position of the fluorine atoms. The calculations were performed on the mono-, di-, and tri-FPTs in their neutral and ionic species by employing the B3LYP/6-311G(d,p) level of theory. The results obtained revealed that the fluorine-substituted phenyl groups played a fine-tune effect on the properties of the FPT monomers. It was found that the electronic chemical potential and electrophilicity index could be successfully correlated with the electronic character of the substitution via a linear dependence behavior on the Hammet function (σ). Moreover, the calculated first excitation energies for FPTs at the TD-DFT level indicated that both the p- and n-doped states had lower excitation energies than those in the neutral states, and displayed a bathochromic shift in their absorption spectra. The frontier molecular study revealed that the p- and n-doped states had more suitable properties with respect to the unsubstituted PT, reflecting the hole and electron transport characteristics of the FPT derivatives. We hope that the results obtained can be helpful in designing a series of modified materials with the facilities of hole and electron injections and efficient charge transport.

Graphical abstractThe influence of fluorine-substituted phenyl on the structure, electonic, and energetics of fluorophenylthiophenes (FPTs) was investigated by means of the B3LP/6-311(d,p) level of theory.Figure optionsDownload full-size imageDownload as PowerPoint slide