Reactions of PO_xCl_y^- ions with O₂(a ¹Δ_g), H₂O, and Cl₂ at 298 K

The rate constants and product branching ratios for the reactions of phosphorus oxychloride anions, PO_xCl_y^- for x = 1-2 and y = 1-3, with O₂(a ¹Δ_g), Cl₂, and H₂O have been measured in a selected ion flow tube (SIFT) at 298 K. A mixture of O₂(a ¹Δ_g) in O₂ has been produced using a recently designed chemical singlet oxygen generator (sparger) with an emission detection scheme adopted previously in our laboratory. The experiments continue a series of investigations into the oxidation reactions of PO_xCl_y^- ions, searching for pathways to the terminal PO₂^- and PO₃^- ions observed in combustion chemistry with POCl₃ present. None of the PO_xCl_y^- ions react with H₂O or O₂(a ¹Δ_g). The O₂(a ¹Δ_g) rate constants have a limit of <1 × 10^-11 cm³ s^-1, except for PO₂Cl^- where a limit of <5 × 10^-11 cm³ s^-1 has been determined. The H₂O rate constants have limits of <1 × 10^-11 cm³ s^-1. All of the PO_xCl_y^- ions react with Cl₂, excluding PO₃^- and PO₂Cl₂^-. Depending on the reactant ion, Cl^-, Cl₂^- or PO₂Cl₂^- product ions form.