ISSN:
1089-7690
Quelle:
AIP Digital Archive
Thema:
Physik
,
Chemie und Pharmazie
Notizen:
The theory of macroscopic observables, which allows a model-independent analysis of collisional relaxation, is applied to selected high-quality experimental data on infrared fluorescence (IRF) from collisional deactivation of azulene excited to ∼30 000 cm−1 by single-photon absorption from a 337 nm laser. Particular attention is paid to obtaining a secure relation between the experimental IRF intensity signal and the azulene bulk-average vibrational energy 〈〈y〉〉. The azulene system turns out to be special in two respects: the initial population distribution immediately following the laser shot can be reasonably approximated by a delta function distribution, and the time decay of 〈〈y〉〉 is a simple exponential over almost half the energy range. Under these conditions, it can be shown that the initial value of the macroscopic bulk-average energy transfer observable 〈〈ΔE〉〉 is identical to the microscopic per collision average 〈ΔE〉, which, in the azulene case, obeys the linear sum rule, i.e., is linearly dependent on excitation energy. These conclusions, which are free of assumptions concerning the nature of the transition probability, as well as the actual numerical values obtained, are in substantial agreement with the results of an earlier analysis of the data, which used a different approach based on the same microcanonical relationship connecting fluorescence intensity and vibrational energy.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1063/1.449804
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