Vacuum-Ultraviolet Photolysis of N2O. II. Deactivation of N2(A 3Σu+*rpar; and N2(B 3Πg)

Quenching of ${\mathrm{N}}_2{\mathrm{(A}}^3{\Sigma }_u^{+})$ , produced during the photodissociation of N₂O with 1470‐Å radiation, was studied using the NO γ‐band emission excited by the process ${\mathrm{N}}_2{\mathrm{(A}}^3{\Sigma }_u^{+}\mathrm{)\hspace{0.17em}+\hspace{0.17em}}\mathrm{NO}\mathrm{\hspace{0.17em}\to \hspace{0.17em}}{\mathrm{N}}_2\mathrm{\hspace{0.17em}+\hspace{0.17em}}\mathrm{NO}{\mathrm{(A}}^2{\Sigma }^{+})$ as a monitor of ${\mathrm{N}}_2{\mathrm{(A}}^3{\Sigma }_u^{+})$ . The relative quenching efficiencies of NH₃, C₂H₂, C₂H₄, NO, C₂N₂, N₂O, O₂, CO, CO₂, H₂ CH₄, N₂, Ar, and He are 2.6, 2.3, 2.2, 1, 0.8, 0.091, 0.054, 0.036, < 4 × 10⁻⁴,≤ 10⁻⁴, < 10⁻⁴, < 10⁻⁴, < 10⁻⁴, and < 10⁻⁴. At 1236 Å the $B^3{\Pi }_g$ state of N₂ is produced in N₂O photolysis and the variation of the intensity of N₂O first positive emission with N₂⁰ pressure was used to evaluate the quenching rate of ${\mathrm{N}}_2{\mathrm{(B}}^3{\Pi }_g)$ by N₂O. The value obtained was 1.6 × 10⁻¹⁰ cm³ molecule⁻¹·sec⁻¹. Quenching efficiencies for other gases were determined relative to N₂O and hence absolutely. The values obtained for NO, CO₂, O₂, CO, H₂, N₂, Ar, and He are ∼2.4 × 10⁻¹⁰, 1.5 × 10⁻¹⁰, 1.1 × 10⁻¹⁰, 8.5 × 10⁻¹¹, 4.6 × 10⁻¹¹, 2.7 × 10⁻¹¹, 1.6 × 10⁻¹², and 8 × 10⁻¹³ cm³ molecule⁻¹·sec⁻¹.