The kinetic parameters for intramolecular excimer formation from the meso and racemic diastereoisomers of 2,4-DI(2-pyrenyl) pentane: evidence for rapid conformer interconversion
✍ Scribed by Klaas A. Zachariasse; Gert Duveneck; Wolfgang Kühnle; Peter Reynders; George Striker
- Publisher
- Elsevier Science
- Year
- 1987
- Tongue
- English
- Weight
- 820 KB
- Volume
- 133
- Category
- Article
- ISSN
- 0009-2614
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✦ Synopsis
Absorption and fluorescence spectra of the meso and racemic diastereoisomers of 2,4-di( 2-pyrenyl)pentane (ZDPP) which form intramolecular excimers in methylcyclohexane at 25°C are presented. From time-correlated single-photon counting measurements of the double-exponential monomer and excimer fluorescence decays, the rate constants for excimer formation and dissociation and the excimer lifetime have been determined. These data are compared with similar data obtained for the related compounds 1,3_di(2_pyrenyl)propane and 1,3-di( 2-pyrenyl)butane. It is concluded that the singlet excited state monomer conformers of 2DPP interconvert on a subnanosecond time scale.