Photofragmentation dynamics and dissociation energies of MoO and CrO

TL;DR

This study uses velocity map imaging to investigate the photofragmentation dynamics and dissociation energies of MoO and CrO molecules, providing detailed insights into their fragmentation pathways and energy thresholds.

Contribution

It introduces a specialized velocity map imaging setup for neutral metal-containing molecules and reports precise dissociation energies for MoO and CrO.

Findings

Dissociation into specific atomic quantum states identified.

Ground state dissociation energies precisely measured.

Multiple product channels observed at different photon levels.

Abstract

Neutral metal-containing molecules and clusters present a particular challenge to velocity map imaging techniques. Common methods of choice for producing such species such as laser ablation or magnetron sputtering typically generate a wide variety of metal-containing species and, without the possibility of mass-selection, even determining the identity of the dissociating moiety can be challenging. In recent years, we have developed a velocity map imaging spectrometer equipped with a laser ablation source explicitly for studying neutral metal-containing species. Here, we report the results of velocity map imaging photofragmentation studies of MoO and CrO. In both cases, dissociation at the two- and three-photon level leads to fragmentation into a range of product channels, some of which can be confidently assigned to particular Mo (Cr) and O atom quantum states. Analysis of the kinetic energy release spectra as a function of photon energy allows precise determination of the ground state dissociation energies of MoO,respectively.