Instantaneous fluorescence quantum yield - A new quantity with characteristic "fingerprints" for excited-state processes

Citation
K. Teuchner et al., Instantaneous fluorescence quantum yield - A new quantity with characteristic "fingerprints" for excited-state processes, J FLUORESC, 9(1), 1999, pp. 67-71
Citations number
9
Categorie Soggetti
Spectroscopy /Instrumentation/Analytical Sciences
Journal title
JOURNAL OF FLUORESCENCE
ISSN journal
10530509 → ACNP
Volume
9
Issue
1
Year of publication
1999
Pages
67 - 71
Database
ISI
SICI code
1053-0509(199903)9:1<67:IFQY-A>2.0.ZU;2-H
Abstract
The instantaneous fluorescence quantum yield phi(ins)-a new quantity for fl uorescence studies defined as the ratio of the fluorescence intensity to th e optical density, both measured at the moment of the maximum of the exciti ng pulse-proves to be a very sensitive function for excited-state processes . Dependent on the excitation intensity phi(ins) exhibits characteristic fe atures (maxima/minima) indicating, for example, excited-state absorptions a nd annihilation processes. phi(ins) is therefore more informative as the in tensity dependence of the usually utilized fluorescence yield, the informat ion content of which is restricted because this function is hardly structur ed. In the paper the influences of specific molecular parameters (excited-s tate absorption cross section, annihilation constant) on phi(ins) are given , problems of the experimental accessibility of phi(ins) are discussed, and an experimental setup for determination of this new quantity is presented. The application of the method is demonstrated for identification of excite d-state absorptions of organic molecules in solution.