The anion photoelectron (PE) spectra of CexOyHz− products formed in sequential reactions between cerium oxide and hydroxide reactions with water are presented and interpreted with supporting density functional theory calculations. The PE spectra of CexOyHz− (x = 2, 3) complexes formed in the sequence of reactions initiated with CexOx− + H2O, exhibit a prominent photodetachment transition indicating that the highest occupied molecular orbital in these species can be described as combinations of Ce 6s atomic orbitals. The electrons in these diffuse orbitals reliably have low binding energies in the range of 0.6–1 eV. The combination of poor orbital overlap and low binding energy is amenable to ionic Ce[sbnd]OH bond formation in reactions with water, rather than Ce[dbnd]O bond formation, which is observed in more reduced clusters that have occupied Ce 5d-based molecular orbitals. Spectral simulations based on computational results, which predict numerous close-lying spin states arising from the singly occupied 4f orbital on each Ce center, support specific structural assignments for the Ce2OyHz− cluster series. A range of Ce3OyHz− products also exhibit the characteristic Ce 6s-based MO photodetachment transition. Based on comparison with calculations that predict stable cerium hydride structures, we infer that the sequence of Ce3OyHz− + H2O reactions proceeds along a path of metastable structures.
- Anion photoelectron spectroscopy
- Cerium oxide clusters
- Electronic structure-reactivity relationship
- Water reactivity
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- Physical and Theoretical Chemistry