Near-resonant electronic energy transfer in the electronic quenching of NO A 2Σ+ by hydrocarbons and ammonia

We report rate coefficients for the electronic quenching of NO A 2Σ+ v=0 by several hydrocarbon fuel gases, methane, ethane, propane, ethene, and ethyne, and by ammonia over a wide temperature range (300–2300 K). High temperature data is obtained behind reproducible shock waves. High-temperature quenching of NO by many species has previously been explained by a charge-transfer (harpoon) model. However, we find such a model unable to explain a portion of the quenching behavior reported here. Instead, we propose that a near-resonant electronic energy transfer mechanism is active.