Femtosecond reaction dynamics of Rydberg states. Methyl iodide
Femtosecond reaction dynamics of Rydberg states (6p ^2E_(1/2) and 7s^2E_(3/2)) in methyl iodide are reported. The observed ultrafast decay and the large isotope effect reflect the Rydberg-valence potentials crossing to yield CH_3 + I. The dependence of the dynamics on the vibrational mode is studied with focus on the character of the mode and the coherent coupling. Molecular quantum dynamics simulations are also reported.