Knowledge Bank

Continuing our studies of functionalized naphthalenes, we report here the results of $S1\leftarrow S0$ experiments on 2-vinylnaphthalene in both supersonic jets and beams. At low resolution, the spectrum is dominated by low frequency bands associated with the torsional motion of the vinyl group, built upon two distinguishable electronic origins. High resolution experiments on several of these bands make possible an assignment of the two origins to cis and trans rotamers, and assignments of the torsional level structure associated with each. We report the transition moment orientations and rotational constants of each band, and show how trends in these parameters may be used to probe motion along the torsional coordinate. Evidence for non-rigid behavior at high excess energies also will be described.