Kinetics of the reactions Br + NO₂ + M and I + NO₂+ M

The reactions Br + NO₂ + M → BrNO₂ + M (1) and I + NO₂ + M → INO₂ + M (2) have been studied at low pressure (0.6-2.2 torr) at room temperature and with helium as the third body by the discharge-flow technique with EPR and mass spectrometric analysis of the species. The following third order rate constants were found k₁₍₀₎ = (3.7 ± 0.7) × 10⁻³¹ and k₂₍₀₎ = (0.95 ± 0.35) × 10⁻³¹ (units are cm⁶ molecule⁻² s⁻¹). The secondary reactions X + XNO₂ → X₂ + NO₂ (X = Br, I) have been studied by mass spectrometry and their rate constants have been estimated from product analysis and computer modeling.