### Abstract

The lowest photoexcited triplet state of thiophene oligomers (nT) with n = 2 - 8 has been investigated by pulsed EPR spectroscopy. The characteristic EPR lineshape is analyzed by performing spectral simulations. The determined D values decrease with increasing chain length showing a linear dependence on the inverse chain length. Furthermore conformational effects have been observed. We compare the results with theoretical calculations of the zero-field splitting parameters. The calculations are based on a semiempirical 'one electron per site' model including electron-electron interactions. The computed D values are in excellent agreement with the EPR data. The chain length dependence of D could be rationalized by computing electron spin densities and bond length distortions, which clearly indicate that the triplet excitation reaches a finite extention over about four thiophene rings.

Original language | English |
---|---|

Pages (from-to) | 607-608 |

Number of pages | 2 |

Journal | Synthetic Metals |

Volume | 84 |

Issue number | 1-3 |

Publication status | Published - Jan 1997 |

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### Keywords

- Electron spin resonance
- Excited states
- Oligothiophenes

### ASJC Scopus subject areas

- Electronic, Optical and Magnetic Materials
- Materials Chemistry
- Polymers and Plastics

### Cite this

*Synthetic Metals*,

*84*(1-3), 607-608.

**Zero-field splitting of the lowest excited triplet state in thiophene oligomers. An experimental and theoretical investigation.** / Bennati, M.; Grupp, A.; Mehring, M.; Nemeth, K.; Surján, P.; Bäuerle, P.

Research output: Contribution to journal › Article

*Synthetic Metals*, vol. 84, no. 1-3, pp. 607-608.

}

TY - JOUR

T1 - Zero-field splitting of the lowest excited triplet state in thiophene oligomers. An experimental and theoretical investigation

AU - Bennati, M.

AU - Grupp, A.

AU - Mehring, M.

AU - Nemeth, K.

AU - Surján, P.

AU - Bäuerle, P.

PY - 1997/1

Y1 - 1997/1

N2 - The lowest photoexcited triplet state of thiophene oligomers (nT) with n = 2 - 8 has been investigated by pulsed EPR spectroscopy. The characteristic EPR lineshape is analyzed by performing spectral simulations. The determined D values decrease with increasing chain length showing a linear dependence on the inverse chain length. Furthermore conformational effects have been observed. We compare the results with theoretical calculations of the zero-field splitting parameters. The calculations are based on a semiempirical 'one electron per site' model including electron-electron interactions. The computed D values are in excellent agreement with the EPR data. The chain length dependence of D could be rationalized by computing electron spin densities and bond length distortions, which clearly indicate that the triplet excitation reaches a finite extention over about four thiophene rings.

AB - The lowest photoexcited triplet state of thiophene oligomers (nT) with n = 2 - 8 has been investigated by pulsed EPR spectroscopy. The characteristic EPR lineshape is analyzed by performing spectral simulations. The determined D values decrease with increasing chain length showing a linear dependence on the inverse chain length. Furthermore conformational effects have been observed. We compare the results with theoretical calculations of the zero-field splitting parameters. The calculations are based on a semiempirical 'one electron per site' model including electron-electron interactions. The computed D values are in excellent agreement with the EPR data. The chain length dependence of D could be rationalized by computing electron spin densities and bond length distortions, which clearly indicate that the triplet excitation reaches a finite extention over about four thiophene rings.

KW - Electron spin resonance

KW - Excited states

KW - Oligothiophenes

UR - http://www.scopus.com/inward/record.url?scp=0030707155&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0030707155&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:0030707155

VL - 84

SP - 607

EP - 608

JO - Synthetic Metals

JF - Synthetic Metals

SN - 0379-6779

IS - 1-3

ER -