Knowledge Bank

We have obtained numerous rotationally resolved trans-stilbene fluorescence excitation spectra in a range of excess energies from - 0 to - $1200cm-1$ above the $S1$ origin using the high resolution spectrometer operating in the ultraviolet. An analysis of the $000$ band has recently been $reported.2$ Higher energy bands exhibit diffuse structure long before the experimentally observed rapid decrease in fluorescence $lifetime3$ thought to be associated with light-induced trans-cis isomerization. We report some results and ongoing progress in our rotational spectroscopic analysis yielding molecular geometry information which is clearly relevant to understanding trans-stilbene and its dynamic behavior following the absorption of light. We also report recent elucidation of the structure of argon-stilbene complexes and some possible strategies for obtaining 'dynamical' Information directly from studies in the frequency domain.