Reaction of hydrogen atoms with singlet delta oxygen (O₂(a¹Δ_g)). Is everything completely clear?

In this paper, a comprehensive analysis of the reaction H  +  O₂(a ¹Δ_g)  →  products and its channels, including available experimental data, theoretical estimations and kinetic studies, was carried out. A possible intrinsic mechanism of the reaction H  +  O₂(a ¹Δ_g)  →  products, taking into account Renner–Teller coupling between the lowest doublet ²A′ and ²A″ states of a HO₂ molecule was suggested. The proposed mechanism allows qualitative justification of the available data on the high probability for the quenching reaction: H  +  O₂(a ¹Δ_g)  →  H  +  O₂(³Σ_g). The effect of the reactions, including electronically excited ${\text{HO}}_2^{\ast }$ molecules on the evaluation of temperature dependencies for the total and branching rate constants of the reaction H  +  O₂(a ¹Δ_g)  →  products at low temperatures, was investigated. The value of the reaction H  +  O₂(a ¹Δ_g)(+M)  →  HO₂(²A′,²A″)(+M) rate constant was evaluated from shock tube experiments on O₂(a ¹Δ_g) quenching in a lean H₂–O₂–O₂(a ¹Δ_g) mixture. Based on the obtained results, temperature and pressure dependencies for the rate constants of the reaction H  +  O₂(a ¹Δ_g)  →  product channels were recommended for the simulations, together with the proposed kinetic sub-mechanism for O₂(a ¹Δ_g) chemistry in H₂–O₂ mixtures. (paper)