Laser-ablated Sc atoms react with Oz during condensation in excess argon to give ScO, OScO, and (O-2)ScO as major products, which are identified from oxygen isotopic substitution on their matrix infrared spectra. The linear suboxide molecule ScOSc is a minor product. Annealing allows further association to form ScO3, (ScO)(2) and Sc(O-2)(2). The OScO molecule is bent: based on the oxygen-18 shift in the nu(3) mode, the valence angle is 128 +/- 4 degrees. The nu(3) fundamental of OScO at 722 cm(-1) is substantially lower than the ScO fundamental at 976 cm(-1), which is in accord with weaker bonds in the dioxide. Similar reactions in excess nitrogen give evidence of extensive ligation.