A classical trajectory study of intramolecular vibrational relaxation and unimolecular decomposition in methyl hydroperoxide

Publisher Website
Google Scholar
Abstract
This paper presents a quasiclassical trajectory study of the energy flow that occurs consequent to high‐overtone excitations of either a CH or an OH local mode in methyl hydroperoxide, CH3 OOH. The potential energy surface employed is an empirical one based on available spectroscopic, thermodynamic, and theoretical data. Energy initially localized in a CH stretch transfers irreversibly on the time scale of the calculations into the methyl bending modes within 0.2 ps. Transfer of energy out of the methyl group to the rest of the molecule occurs more slowly. An initially excited OH bond retains energy longer than does a CH bond and, unlike the energy transfer for an excited CH stretch, partial recurrences in the energy content of the OH mode occur for some excitations. Vibrational resonances are important in determining the rates and pathways of energy flow in the molecule. At total energies near 104 kcal/mol the rate of the O–O bond scission is twice as fast for OH excitation as it is for CH excitation.