Heterogeneous perturbations in the Doppler-free S1 ← S0 two-photon spectrum of benzene: Evidence for intrastate coupling

✍ Scribed by E. Riedle; H. Stepp; H.J. Neusser

• Publisher: Elsevier Science
• Year: 1984
• Tongue: English
• Weight: 650 KB
• Volume: 110
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(84)87069-4

✦ Synopsis

Rotational perturbations are identified in Doppler-free two-photon spectra of the 14' 9 and 14r 0 1' 9 vibronic bands in ChH6. Evidence is found that Coriolis coupling between some of the rotational levels of two distinct vibrational states within St is the mechanism responsible. Thin coupling mechanism is thought to be responsible for irreversible intramolecular relaxation at higher excess energies and higher vibrational state densities.

1. introduction

Recently it was noted that relaxation rates of benzene S, vibronic levels deduced from fluorescence yield measurements [1] differ from those deduced from b.i&er-resolution band contour measurements [3]. This deviation might be explained by intramolecular vibrational relaxation (IVR) prior to electronic relaxation in this excess energy range. Prior information on IVR at high vibrational excess energies was drawn from frequency-resolved emission spectra [3] (for a review, see ref. [4]) under ambient gas and cooled supersonic beam conditions, as well as from oscillatory (quantum beat) emission behaviour [5]. In none of these studies have single rovibronic