Stability, optical and charge transport properties of saddle-shaped cyclooctatetrathiophene (COTh) isomers: a theoretical study

Abstract

Design and structure–property relationship studies of the system containing a cyclooctatetraene (COT) ring fused with four 5-membered heterocyclic rings have been reported. The five-membered heterocycle chosen for the present study is thiophene and based on connectivity with COT, cyclooctatetrathiophene (COTh) exists in fifteen geometrical isomers. The systematic reviews of all the isomers of COTh, are carried out by utilizing density functional theory (DFT) and time dependent-density functional theory (TD-DFT) calculations. Electronic excitations, reorganization energies (transport properties of electron and hole), electron affinities (EA) and ionization potentials (IP) of all the isomers are reported. Based on the outcomes of this study, we suggest that one of the isomers, among all fifteen possible isomers, is better suited for applications that take advantage of its charge transport properties.

GRAPHICAL ABSTRACT

KEYWORDS:

• Cyclooctatetraene (COT)
• cyclooctatetrathiophene (COTh)
• ionization potentials (IP)
• electron affinities (EA)
• charge transport properties

Acknowledgments

PC thanks SERB- New Delhi, India (grant number SB/FT/CS-101/2014) for financial support.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by Science and Engineering Research Board: [Grant Number SB/FT/CS-101/2014].