Photodissociation dynamics of tert-butyl hydroperoxide at 266 nm: Degenerate four-wave mixing observation of OH state distribution

Degenerate four-wave mixing spectroscopy has been used to study the photodissociation dynamics of tert-butyl hydroperoxide (t-BuOOH) at 266 nm, long-wavelength tail of the ultraviolet (UV) absorption continuum. The nascent rotational distributions, spin-orbit state ratio, and Λ-doublet population ratio of the OH (X²Π) fragments have been extracted. No vibrationally excited OH was observed. The rotational distribution peaked at N^″=5. The average rotational energy was estimated to be 4.2% of the available energy. A slight preference for the Π^- Λ-doublet component and a statistical distribution of the spin-orbit states were observed. The experimental observations are similar to those found for OH from H₂O₂ photodissociation and are consistent with dissociation via a repulsive excited state.