| Autor: |
Horwitz, James S., Kohler, Bryan E., Spiglanin, Thomas A. |
| Předmět: |
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| Zdroj: |
Journal of Chemical Physics; 9/1/1985, Vol. 83 Issue 5, p2186, 5p, 3 Charts, 3 Graphs |
| Abstrakt: |
We report the two-photon excitation spectrum and decay kinetics of the two-photon prepared states for diphenylbutadiene in a helium free jet. The spectrum is that of a symmetry allowed two-photon transition and is assigned using 17 harmonic fundamentals. A reexamination of the previously reported one-photon excitation spectrum allows the assignment of several additional u symmetry fundamentals of diphenylbutadiene’s excited 1Ag state. Curves of intensity vs time for light detected at two times the wave number frequency of the laser minus a Stoke’s shift of between 1000 and 9000 cm-1 show two components. One, due to two-photon resonance enhanced hyper-Raman scattering, reproduces the temporal profile of the exciting laser. The other, due to fluorescence from the excited 1Ag state, decays exponentially. The fluorescence lifetime decreases with increasing excitation frequency from 100 ns for 0–0 band excitation to 13 ns for excitation at 1235 cm-1 above the origin, consistent with the onset of a nonradiative decay channel previously observed for diphenylbutadiene in one-photon studies. Above this energy only hyper-Raman scattering is detected. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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