Hydration of a structured excess charge distribution: Infrared spectroscopy of the O2−⋅(H2O)n, (1⩽n⩽5) clusters

• DOI: 10.1063/1.1338529
• Publication Date: 2002-07-26T14:14:42Z
• Authors: J. Mathias Weber; Jude A. Kelley; William H. Robertson; Mark A. Johnson
• Keywords: Trimer; Tetrahydrate

To explore how a structured excess charge distribution affects the hydration of an anion, we report mid-IR, argon predissociation spectra for hydrated superoxide cluster anions, O2−⋅(H2O)n, 1⩽n⩽5. This size range was chosen to establish evolution structures through putative shell closing [Weber et al., Science 287, 2461 (2000)] at tetrahydrate. Whereas observed bonding motifs n⩽4 are those single water molecules and dimeric subclusters bound ion, pentahydrate spectrum displays strong bands in region typically associated with ring modes trimer. The present results reinforce conclusion that tetrahydrate adopts especially robust structure which each molecule forms ionic H bond one lobes π* highest occupied molecular orbital superoxide.