Structure investigation of CoxOy+ (x=3–6, y=3–8) clusters by IR vibrational spectroscopy and DFT calculations

Cationic cobalt 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 Co x O y + · O 2 \hbox{$\overset{h\nu}{\rightarrow}$} → hν Co x O y + + O 2 in the 260–1400 cm -1 range. Density functional theory was used to investigate the geometry and spin configuration of Co x O y + clusters in the range x = 3-6, y = 3-8. Lowest energy structures with IR vibrational spectra which agree reasonably well with the experiment are found for several cluster sizes. The magnetic ordering within all but one cluster size, Co 6 O 8 + , is found to have an antiferromagnetic component.