Energy Transfer Reactions of N2(A3Σu+). IV. Measurement of the Radiative Lifetime and Study of the Interaction with Olefins and Other Molecules

The rate constants and products from the interaction of the first triplet state of nitrogen, ${\mathrm{N}}_2{\mathrm{(A\hspace{0.17em}}}^3{\Sigma }_u^{+})$ , with C₂H₄ and cis‐C₄H₈ have been measured in a discharge flow apparatus. The reactions are fast with rate constants near 10¹⁴ cc mole⁻¹·sec⁻¹ and give products which are typical of other triplet—triplet donor reactions with olefins. The product yields were used to measure the concentration of ${\mathrm{N}}_2{\mathrm{(A\hspace{0.17em}}}^3{\Sigma }_u^{+})$ molecules. This concentration was combined with the absolute emission intensity from the ${\mathrm{N}}_2{\mathrm{(A\hspace{0.17em}}}^3{\Sigma }_u^{+}{\mathrm{-X\hspace{0.17em}}}^1{\Sigma }_g^{+})$ transition to estimate the radiative lifetime of $({\mathrm{N}}_2{\mathrm{A\hspace{0.17em}}}^3{\Sigma }_u^{+}{\mathrm{;\; v}}^{\prime }\text{=0, 1)}$ . The data support the recently published low lifetime value reported by Shemansky and Carleton. Rate constants were measured for quenching of ${\mathrm{N}}_2{\mathrm{(A\hspace{0.17em}}}^3{\Sigma }_u^{+})$ by acetylene, cyanogen, propene, benzene, 1,4‐butadiene, cyclopropane, oxygen, sulfur dioxide, carbon monoxide, nitrous oxide, and ammonia. The first‐order removal of ${\mathrm{N}}_2{\mathrm{(A\hspace{0.17em}}}^3{\Sigma }_u^{+})$ by the quartz surface also was characterized.