Kinematic constraints on the final state interaction in photodissociation processes: Predissociative mechanism of NO 2 at 337 nm

Abstract

Rotational population distributions of NO photofragments in the second vibrational excited state from the photofragmentation of NO 2 at 337 nm are evaluated numerically via a kinematic distribution function. The kinematic constraints on the final state interaction in the photofragmentation process of NO 2 reveal a definitive mechanism of predissociation when the numerically calculated distributions are compared with experimental data. The excited 2B 2 state at 29665 cm −1 predissociates into the continuum of the ground 2A 1 electronic state and the anomalous rotational population distributions result from the recoil of oxygen atoms along two crossing points at 3.678 eV between the 2B 2 and 2A 1 potential energy surfaces. Although these two surfaces intersect on a double cone, the narrow ranges of recoil angles in the predissociation of NO 2 follow strictly after the conservation of energy and the Franck-Condon principle.