Valence and Structure Isomerism of Al2FeO4+: Synergy of Spectroscopy and Quantum Chemistry.
J Am Chem Soc
; 142(42): 18050-18059, 2020 Oct 21.
Article
em En
| MEDLINE
| ID: mdl-33031700
ABSTRACT
We provide spectroscopic and computational evidence for a substantial change in structure and gas phase reactivity of Al3O4+ upon Fe-substitution, which is correctly predicted by multireference (MR) wave function calculations. Al3O4+ exhibits a cone-like structure with a central trivalent O atom (C3v symmetry). The replacement of the Al- by an Fe atom leads to a planar bicyclic frame with a terminal Al-Oâ¢- radical site, accompanied by a change from the Fe+III/O-II to the Fe+II/O-I valence state. The gas phase vibrational spectrum of Al2FeO4+ is exclusively reproduced by the latter structure, which MR wave function calculations correctly identify as the most stable isomer. This isomer of Al2FeO4+ is predicted to be highly reactive with respect to C-H bond activation, very similar to Al8O12+ which also features the terminal Al-Oâ¢- radical site. Density functional theory, in contrast, predicts a less reactive Al3O4+-like "isomorphous substitution" structure of Al2FeO4+ to be the most stable one, except for functionals with very high admixture of Fock exchange (50%, BHLYP).
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Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Ano de publicação:
2020
Tipo de documento:
Article