Subpicosecond predissociation dynamics of the methyl radical Rydberg 3 <i>s</i> state

Abstract

The subpicosecond dissociation dynamics of the methyl radical 3 s Rydberg state have been examined using rotational resonance Raman spectroscopy. The rovibronic dependence of the excited state predissociation rates and lifetimes are obtained for the B̃ state origin vibrational level of CH3 and CD3. Analysis of the tunneling rates using a cubic potential barrier yields estimates for the height (2200 cm−1) and position of the barrier along the dissociation coordinate (1.38 Å). A comparison of the potential energy surface parameters for the Rydberg 3 s states of methyl radical and ammonia is presented.