Vector correlations in the vibrational predissociation of hydrogen fluoride dimer

Abstract

The influence of laser polarization direction on the photofragment angular distributions resulting from vibrational predissociation of HF dimer has been studied in an effort to establish the correlation between the direction of the transition moment in the parent molecule (μ) and the recoil velocity vector of the fragments (ν). This is possible, even for the long-lived predissociative states considered here, since the dimer is initially excited to a single rotational level, with a well-defined time-independent, anisotropic rotational wave function. The mathematical framework appropriate for treating the photodissociation of this asymmetric rotor is presented and used to extract anisotropy parameters for the various initial states. The results clearly show that the recoil velocity vector of the fragments is preferentially aligned along the a axis of the dimer. The implications of this for the associated dynamics are discussed. Data of this type is directly related to the center-of-mass differential photodissociation cross section and thus can be used to establish further points of comparison with the theoretical calculations that are becoming possible for systems of this type.