Infrared spectra of Ti + N-2, TiO2 + N-2, Ti + N2O, and TiO2 + N2O systems have been studied in solid argon. The major reaction products TiN2, O2TiN2, and O2Ti(N-2)(2) are identified from the use of different reaction systems. The bands at 1847.1/766.2, 1901.3/909.4, and 1863.5/903.4 cm(-1) are assigned to these molecules, respectively, based on N-15 isotopic substitution. Competition between Ti atom and nitrogen and titanium oxide and nitrogen reactions takes place; small concentrations of TiO and TiO2 in Ti atom systems give the dominant products, indicating the greater reactivity of oxides than the metal atom.