The Role of Linear Alkyl and Alkoxy Side Chains in the Modulation of the Structure and Electrical Properties of Bithiophene:a Theoretical Study

Gregorio Garcia; Andrés Garzón; José M. Granadino-Roldán; Mónica Moral; M. Paz Fernández-Liencres; Amparo Navarro; Manuel Fernández-Gómez

doi:10.1071/CH10050

RESEARCH ARTICLE

The Role of Linear Alkyl and Alkoxy Side Chains in the Modulation of the Structure and Electrical Properties of Bithiophene:a Theoretical Study

Gregorio Garcia ^A , Andrés Garzón ^A , José M. Granadino-Roldán ^A , Mónica Moral ^A , M. Paz Fernández-Liencres ^A , Amparo Navarro ^A and Manuel Fernández-Gómez ^A ^B

+ Author Affiliations

- Author Affiliations

^A Departamento de Química Física y Analítica, Universidad de Jaén, Paraje las Lagunillas, E 23071, Jaén, Spain.

^B Corresponding author. Email: mfg@ujaen.es

Australian Journal of Chemistry 63(8) 1297-1306 https://doi.org/10.1071/CH10050
Submitted: 27 January 2010 Accepted: 3 June 2010 Published: 10 August 2010

Abstract

In the present work, we have studied from a theoretical perspective the geometry and electronic properties of 2,2′-bithiophene (BT) and its derivatives 3,4′-alkyl-2,2′-bithiophene (3,4′ABT) and 3,4′-alkoxy-2,2′-bithiophene (3,4′OABT). Properties such as planarity, bond lengths, electron density, highest occupied molecular orbital → lowest unoccupied molecular orbital (HOMO → LUMO) excitation energy and π-delocalization energy, which are related to the electrical conductivity, were calculated and analyzed as a function of both the nature and length of the substituent. The oxidation process was also studied for the single-polaronic state. The ionization potential and the intramolecular reorganization energy were calculated following the semiclassical Marcus treatment. As a conclusion, the introduction of alkoxy chains in 3,4′-positions improves the electrical properties with respect to the bithiophene molecule and the corresponding alkyl derivatives.

Acknowledgements

The authors gratefully acknowledge Consejería de Innovación, Ciencia y Empresa, Junta de Andalucía (PAI-FQM 337 contract and FQM-P06–01864 project), for financial support, and Centro Informático Científico de Andalucía (CICA) for allocation of computational resources. One of us (G.G.) thanks the Unidad Asociada CSIC-Universidad de Jaén for a predoctoral grant.

References

The Role of Linear Alkyl and Alkoxy Side Chains in the Modulation of the Structure and Electrical Properties of Bithiophene:a Theoretical Study

Abstract

Acknowledgements

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