Ferrimagnetic cagelike Fe4O6 cluster: Structure determination from infrared dissociation spectroscopy

[摘要] Cationic iron-oxide clusters of several sizes and stoichiometries have been synthesized and studied isolated in the gas phase. Vibrational spectra of the clusters have been measured using resonant IR-induced dissociation of FenOm+2+ --> FenOm++O-2 in the 250-1250 cm(-1) range. Density-functional theory was used to investigate the geometry and spin configuration of the representative Fe4O60/+ cluster. Its lowest-energy state was found to be an almost tetrahedral cagelike structure with a ferrimagnetic arrangement of spins, resulting in total cluster spin of S=5 for the neutral cluster. These results were confirmed for Fe4O6+ by the comparison of the calculated infrared spectrum to the experimentally obtained one.

[关键词] DENSITY-FUNCTIONAL CALCULATIONS;METAL-OXIDE CLUSTERS;ABLATED IRON ATOMS;TRANSITION-METAL;RAMAN-SPECTROSCOPY;OXYGEN MOLECULES;CATIONS;SPECTRA