Rate constants for deactivation of N2(A) v′=0,1 by O2

Abstract

The removal of N₂(A ³Σ_u⁺, v′=0,1) by O₂ has been studied in a room temperature discharge‐flow apparatus by monitoring the temporal decay of the 0,6 and 1,10 bands of the Vegard–Kaplan system. Rate constants for the reaction with O₂ are (2.3±0.4) and (4.1±0.7)×10⁻¹² cm³ molecule⁻¹ s⁻¹ for v′=0 and 1, respectively. The rate constant measured for v′=0 is about 35% lower than commonly accepted values for the rate constant for quenching N₂(A) by O₂. This discrepancy is shown to result from the fact that most other studies used a tracer to monitor the N₂(A) number density. The rate of decay of the tracer reflects both the decay of the v′=0 and v′=1 levels of N₂(A) and its value is midway between the decay rates of the individual vibrational levels.