Electronic excitations of the fullerene–thiophene-derived dyads

• Published in: Synthetic metals 2011-02, Vol.161 (3-4), p.229-234
• Main Authors: Barszcz, Bolesław, Laskowska, Barbara, Graja, Andrzej, Park, Eun Young, Kim, Tae-Dong, Lee, Kwang-Sup
• Format: Article
• Language: English
• Subjects: Absorption spectroscopy; Atomic and molecular clusters; Atomic and molecular physics; Density functional theory; Electronics; Exact sciences and technology; Excitation; Excitation spectra; Fullerene; Fullerenes; Mathematical analysis; Oligomers; Optical properties of clusters; Physics; Studies of special atoms, molecules and their ions; clusters; TD-DFT; Thiophene; UV–vis spectra
• ISSN: 0379-6779; 1879-3290
• DOI: 10.1016/j.synthmet.2010.11.024

▶ The set of five fullerene–thiophene–derived dyads have been investigated. ▶ UV–vis absorption spectroscopy and time dependent DFT calculations have been used. ▶ In four dyads the strongest electronic excitations are due to fullerene part. ▶ The strongest electronic excitations in 3T-F are due to oligothiophene part. ▶ The HOMO-LUMO gap in 3T-F is smaller than in the other dyads. The electronic absorption spectra of fullerene–thiophene-derived dyads in the UV–vis range have been investigated and discussed taking into account the results of time-dependent density functional theory (TD-DFT) calculations. It was found that the strongest excitations in the dyads are mainly related to the excitations of the fullerene part with some influences from the thiophene-derived part and intramolecular charge transfer processes. The 3T–F dyad significantly differs from the others — the calculated HOMO–LUMO gap in this molecule is significantly lower than in other dyads. This difference is caused by the length of the oligomer and probably by the electron delocalization connected with that length.