Kinetics and Products of the Reactions of Fluorine Atoms with ClNO and Br 2 from 295 to 950 K

Yuri Bedjanian (1)

1 ICARE - Institut de Combustion, Aérothermique, Réactivité et Environnement

The kinetics and products of the reactions of F atoms with Br2 and ClNO have been studied in a flow reactor coupled with an electron impact ionization mass spectrometer at nearly 2 Torr total pressure of helium and over a wide temperature range, T = 295–950 K. The rate constant of the reaction F + ClNO → products (1) was determined under pseudo-first order conditions, monitoring the kinetics of F atom consumption in excess of ClNO. The measured temperature independent rate constant, k1 = (1.29 ± 0.13) × 10–10 cm3 molecule–1 s–1 (T = 299–950 K), was found to be in excellent agreement with the only previous low temperature study which allowed to recommend the value of k1 in an extended temperature range, 228–950 K. FCl and Cl atoms were observed as the reactions products (corresponding to two reaction pathways: Cl-atom abstraction and replacement with fluorine atom, respectively) with the independent of temperature, in the range 295–948 K, yields of 0.68 ± 0.10 and 0.32 ± 0.05, respectively. Rate constant of the reaction F + Br2 (2), k2 = (1.28 ± 0.20) × 10–10 cm3 molecule–1 s–1, determined using both absolute and relative rate methods, was found to be independent of temperature at T = 299–940 K.

Domaines: Chimie théorique et/ou physique

Yuri Bedjanian. Kinetics and Products of the Reactions of Fluorine Atoms with ClNO and Br 2 from 295 to 950 K. Journal of Physical Chemistry A, 2017, 121 (44), pp.8341-8347. ⟨10.1021/acs.jpca.7b08956⟩. ⟨hal-02123090⟩