Trap formation and energy transfer in the hexapyropheophorbide a – fullerene C60 hexaadduct molecular system
| Autor: | S. Al-Omari, Eugeny A. Ermilov, Norbert Jux, Andreas Hirsch, St. Hackbarth, Matthias Helmreich, Beate Röder |
|---|---|
| Rok vydání: | 2005 |
| Předmět: |
Fullerene
Materials science Absorption spectroscopy business.industry Singlet oxygen Stacking Molecular physics Atomic and Molecular Physics and Optics Electronic Optical and Magnetic Materials chemistry.chemical_compound Dipole Optics chemistry Molecule Moiety Electrical and Electronic Engineering Physical and Theoretical Chemistry Time-resolved spectroscopy Atomic physics business |
| Zdroj: | Optics Communications. 250:95-104 |
| ISSN: | 0030-4018 |
| DOI: | 10.1016/j.optcom.2005.02.039 |
| Popis: | The photophysical properties of the novel hexapyropheophorbide a – fullerene hexaadduct (FHP6) compound were studied using both steady-state and time-resolved spectroscopic methods. It was found that neighboring pyropheophorbide a (pyroPheo) molecules covalently linked to one fullerene moiety due to the length and high flexibility of carbon chains could stack with each other. This structural property is the reason for the possibility of formation of two different types of energy traps, which could be resolved experimentally. One of them is formed via face-to-face stacking of two pyroPheo molecules with parallel to each other direction of the transition dipole moments. The second type of energy trap gives the dominant contribution to the fluorescence signal at registration wavelengths having the oblique geometry or orthogonal direction of the transition dipole moments of the interacting pyroPheo molecules. In any case the dipole–dipole resonant Forster energy transfer between pyroPheo molecules coupled to one fullerene moiety caused a very fast and efficient delivery of the excitation to a trap. As result the fluorescence as well as the singlet oxygen quantum yields of FHP6 were reduced three and two times, respectively, compared to those values of the reference bis pyropheophorbide a – fullerene hexaadduct (FHP1) compound. |
| Databáze: | OpenAIRE |
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