Direct Flow Measurement of O2(b1Σg+) Quenching Rates

Abstract

A relaxation method is developed which permits a direct measurement of O2(b1Σg+) quenching rate constants. An Al wire spiral is used to selectively quench O2(1Σ) which is normally present in discharged oxygen as a steady-state intermediate. The characteristic time for the reestablishment of the O2(1Σ) steady state is used to determine wall and bimolecular quenching rates. With this method, absolute rate constants are obtained from relative intensity measurements of the O2(1Σ) emission at 7619 Å. The rate constant for quenching by H2O is found to be 4.0 ± 0.6 × 10−12 cc sec−1. Rate constants for a number of other quenchers are reported.

Kinetic Studies of the Reactions of O2(bΣg+) with Several Atmospheric Molecules

“…Several other studies 28,29,39,48 are also in good agreement with this recommendation. Again, multiple sources of O 2 ( 1 Σ g + ) were used in these previous studies, and now with our results, multiple methods for determining the rate coefficient.…”

Environmental effects of large igneous province magmatism: a Siberian perspective

“…[1256], Aviles et al, [57] Shi and Barker [1180], and Dunlea et al [421]. Measurements reported by O'Brien and Myers [1004] are lower likely due to an interference from O 2 ( 1 Σ) regeneration.. The results of Derwent and Thrush [385], and Thomas and Thrush [1297] are in agreement with the recommendation.…”

On the role of metastable states in low pressure oxygen discharges

“…In these studies we assumed the quenching coefficient to be 0.1, which is the same value as that assumed in this current study. This assumption is based on the suggestion that the quenching coefficient for the b 1 Σ + g state is about two orders of magnitude larger than that for the a 1 ∆ g state [25].…”