The Counterintuitive Relationship between Orbital Energy, Orbital Overlap, and Bond Covalency in CeF₆^2- and CeCl₆².

ABSTRACT: The 4f orbitals of Ce(IV) have shown appreciably enhanced covalent mixing with ligand orbitals relative to those of Ce(III). Here, X-ray spectroscopy, magnetic susceptibility measurements, and theoretical methods are used to investigate 4f covalency in CeF₆^2- and CeCl₆^2-. These techniques show covalent mixing between Ce 4f and F 2p orbitals to be about 25% less than mixing between Ce 4f and Cl 3p orbitals, placing CeF₆^2- among the most ionic Ce(IV) compounds to-date. However, ligand field analysis using the experimental data shows significantly higher 4f orbital overlap with the F 2p orbitals compared to the Cl 3p. This result is counterintuitive since the Ce-F bonds display less 4f covalency despite their higher orbital ove

SUBMITTER: Branson JA 

PROVIDER: S-EPMC11421006 | biostudies-literature | 2024 Sep

REPOSITORIES: biostudies-literature