Vibrational predissociation spectra of the On−, n = 3–10, 12 clusters: Even–odd alternation in the core ion

We report vibrational predissociation spectra of the On−, n = 3–10, 12 cluster ions in the 700–2400 cm−1 range. The odd numbered clusters are consistent with their identification as O3−⋅(O2)n. The even numbered clusters are based on the O4− core ion, where the first two O2 molecules add to O4− in locations that individually break the symmetry of the core ion, but together restore this symmetry. Beyond O4−⋅(O2)2, subsequent O2 attachment yields bands close to that of neutral O2, indicating that the special character of the O4−⋅(O2)2 cluster is retained.

Graphical abstractAnionic clusters of oxygen (On−), formed in a supersonic free jet, build basically neutral solvent shells upon an ionic core.Figure optionsDownload full-size imageDownload as PowerPoint slide