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Schlagwörter:
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Zusammenfassung:
The infrared photodissociation spectra of He-tagged (Al2O3)nFeO+ (n = 2–5), are reported in the Al-O and Fe-O stretching and bending spectral region (430–1200 cm-1) and assigned based on calculated harmonic IR spectra from density functional theory (DFT). The substitution of Fe for an Al center occurs preferentially at 3-fold oxygen coordination sites located at the cluster rim and with the Fe atom in the +III oxidation state. The accompanying elongation of metal oxygen bonds leaves the Al-O network structure nearly unperturbed (isomorphous substitution). Contrary to the Al2FeO4+ (n = 1), valence isomerism is not observed, which is attributed to smaller M:O ratio (M = Al, Fe) and consequently decreasing electron affinities with increasing cluster size.
