Platinum and palladium atoms produced by laser ablation were reacted with dioxygen diluted in argon during condensation at 10 K. Reaction products, including the M(O-2) and (O-2)M(O-2) complexes prepared with thermal metal atoms, and the platinum oxides PtO, OPtO, PtO3, OOPtO, and (O-2)PtO, were analyzed by matrix infrared spectroscopy. Absorptions due to PdO and OPdO were not identified. Density functional theory (B3LYP) calculations were performed on product molecules, which were identified on the basis of isotopic frequency shifts and correlation with density functional calculations. The most interesting new molecule produced here, linear OPtO, can also be produced by photolysis of the cyclic Pt(O-2) complex.