In this paper we report on the absorption and fluorescence excitation spectra for the S0 → S1 and S0 → S2 transitions of phenanthrene in pulsed planar supersonic expansions. The line profile of the electronic origin of S0 → S2 transition is Lorentzian with a homogeneous width of 11 cm-1 for electronic relaxation in the isolated molecule. The S0 → S2 origin of the isolated molecule, which corresponds to the statistical limit, drastically differs from the same transition of phenanthrene in durene which reveals the features of the intermediate-level structure. The dramatic medium effect on the interstate S2-S1 coupling is attributed to the modification of the electronic energy gap.
|Number of pages||4|
|Journal||Journal of Physical Chemistry|
|State||Published - 1984|