posted on 2020-04-02, 14:29authored byK. S. Molek, Z. D. Reed, A. M. Ricks, M. A. Duncan
Chromium oxide cluster cations, CrnOm+, are produced by laser vaporization in a pulsed nozzle cluster source
and detected with time-of-flight mass spectrometry. The mass spectrum exhibits a limited number of
stoichiometries for each value of n, where m > n. The cluster cations are mass selected and photodissociated
using the second (532 nm) or third (355 nm) harmonic output of a Nd:YAG laser. At either wavelength,
multiphoton absorption is required to dissociate these clusters, which is consistent with their expected strong
bonding. Cluster dissociation occurs via elimination of molecular oxygen, or by fission processes producing
stable cation species and/or eliminating stable neutrals such as CrO3, Cr2O5, or Cr4O10. Specific cation clusters
identified to be stable because they are produced repeatedly in the decomposition of larger clusters include
Cr2O4+, Cr3O6+, Cr3O7+, Cr4O9+, and Cr4O10+.