Fluorescence of 2,3-Diazabicyclo[2.2.2]oct-2-ene Revisited: Solvent-Induced Quenching of the n,π*-Excited State by an Aborted Hydrogen Atom Transfer
In: The Journal of Physical Chemistry A, Jg. 103 (1999-03-01), S. 1579-1584
Online
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Zugriff:
The fluorescence lifetimes of 2,3-diazabicyclo[2.2.2]oct-2-ene (DBO) were determined in a large number of solvents and solvent mixtures, displaying variations from 825 ns in CD3CN to 13 ns in CHCl3. Large deuterium isotope effects (8−11) and significant activation energies (generally 2−15 kJ mol-1) for fluorescence quenching of DBO are observed, which support a novel solvent-induced quenching mechanism via an aborted hydrogen atom transfer. In CCl4 a photoinduced electron-transfer quenching mechanism may compete. The fluorescence quenching by solvent mixtures is not proportional to the mole fraction of the two components, indicating a preferential solvation of the excited state.
| Titel: |
Fluorescence of 2,3-Diazabicyclo[2.2.2]oct-2-ene Revisited: Solvent-Induced Quenching of the n,π*-Excited State by an Aborted Hydrogen Atom Transfer
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| Autor/in / Beteiligte Person: | Scaiano, J. C. ; Wall, Julia ; Greiner, Gerhard ; Rau, Hermann ; Nau, Werner M. ; Olivucci, Massimo |
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| Zeitschrift: | The Journal of Physical Chemistry A, Jg. 103 (1999-03-01), S. 1579-1584 |
| Veröffentlichung: | American Chemical Society (ACS), 1999 |
| Medientyp: | unknown |
| ISSN: | 1520-5215 (print) ; 1089-5639 (print) |
| DOI: | 10.1021/jp984303f |
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