Pi*) states Spectroscopic determination of potential energy surfaces for the out-of-plane ring vibrations of indan and related molecules in their S-0 and S-1 (Pi

The laser induced fluorescence excitation spectra of jet-cooled indan and related moelcules along with their ultraviolet absorption spectra have been used to study their S1 ( ,*) excited states. Far-infrared, Raman, and dispersed fluorescence were utilized to obtain the vibrational data for the S ground states. This allowed the potential energy surfaces (PESs) of these molecules to be determined in terms of the ring-puckering and ring-flapping coordinates for both states. These PESs provide barriers to planarity and conformational structures for these bicyclic molecules. Phthalan has a barrier of 35cm-1 in S0 but no barrier for S1. Coumaran has an S0 barrier of 279 cm-1, while 1,3-benzodioxole has barriers of 171 and 264 cm-1 for S0 and S1, respectively, due to the anomeric effect. The barriers for indan are 1077 cm-1 for S0 and 698 cm-1 for S0. Ab initio calculations in general provide good barrier values for the ground state.

Laane, J., Arp, Z., Sakurai, S., Morris, K., Meinander, N., Klots, T., ... Choo, J.

Laane, J||Arp, Z||Sakurai, S||Morris, K||Meinander, N||Klots, T||Bondoc, E||Haller, K||Choo, J

Spectroscopic determination of potential energy surfaces for the out-of-plane ring vibrations of indan and related molecules in their S-0 and S-1 (Pi, Pi*) states Conference Paper