The products of the reaction of Sc and dioxygen have been reinvestigated. By adding the electron-trapping molecule CCl4 additional information about the IR spectra has been obtained, as well as the observation of new bands. New ab initio calculations are also performed on possible products of the Sc plus O-2 reaction. The previously observed band at 722.5 cm(-1) is assigned as the b(2) mode of ScO2-. Bands arising from ScO+, Sc(O-2)(+), and(O-2)ScO are also assigned. We are still unable to assign any bands to OScO. The problems associated with the computational study of ScO2 are discussed.