MARILYN E. JACOX AND WARREN E. THOMPSON, Sensor Science Division, National Institute of Standards and Technology, Gaithersburg, MD 20899-8441.
The infrared spectrum of cyc-O4+ trapped in solid neon includes a group of combination bands built on ( 1 + 5) of ground-state cyc-O4+. Each peak lies close to a counterpart previously reported in a study of the infrared laser photodissociation spectroscopy of a mass-selected molecular beam. This agreement is consistent with the vibrational assignment of three low-frequency modes of cyc-O4+ that was proposed in the earlier study. The spectra obtained for the isotopologues formed by the substitution of one or two 18O2 moieties suggest the occurrence of interaction with a nearby excited electronic state.