Geometrical structures of cerium oxide cluster cations, CenOm + (n = 2-6, m ≤ 2n), were studied by ion mobility mass spectrometry (IMMS). The most plausible structure for each composition was determined by comparison of a collision cross section (CCS) measured by IMMS with simulated CCSs of several candidate structures obtained from density functional theory (DFT) calculations. For Ce2O2,3 +, Ce3O4,5 +, and Ce5O9 +, the IMMS results were mostly consistent with those of the vibrational spectroscopic study, whereas a more compact structure was suggested for Ce4O7 +. The geometrical structures of some species, Ce4O5,6 +, Ce5O6-8 +, and Ce6O8-12 +, were studied for the first time. For CenO2n + clusters, the IMMS measurements suggested more compact structures than the reported DFT calculations. Structures with a peroxide ion (O2 2-) were found to be the most reasonable for CenO2n + compositions because they are consistent with the experimental results and have the lowest energies among the examined candidate structures, whereas other structures without O2 2- are also possible. These findings offer important insights into the reaction mechanisms involving those clusters.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Physical and Theoretical Chemistry
- Surfaces, Coatings and Films