Premium
Kinetics and Products of the Reactions of F 2 with Br‐Atom and Br 2
Author(s) -
Bedjanian Yuri,
Romanias Manolis N.
Publication year - 2018
Publication title -
international journal of chemical kinetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.341
H-Index - 68
eISSN - 1097-4601
pISSN - 0538-8066
DOI - 10.1002/kin.21171
Subject(s) - chemistry , reactivity (psychology) , reaction rate constant , halogen , kinetics , molecule , chemical kinetics , atmospheric temperature range , yield (engineering) , electron ionization , ionization , analytical chemistry (journal) , organic chemistry , ion , thermodynamics , alkyl , medicine , physics , alternative medicine , pathology , quantum mechanics
ABSTRACT Reactions of F 2 molecules exhibit unusual features, manifesting in high reactivity of F 2 with respect to some closed‐shell molecules and low reactivity toward chemically active species, such as halogen and oxygen atoms. The existing data base on the reactions of F 2 being rather sparse, kinetic and mechanistic studies (preferably over a wide temperature range) are needed to better understand the nature of the specific reactivity of fluorine molecule. In the present work, reactions of F 2 with Br atoms and Br 2 have been studied for the first time in an extended temperature range using a discharge flow reactor combined with an electron impact ionization mass spectrometer. The rate constant of the reaction F 2 + Br → F +BrF (1) was determined either from kinetics of the reaction product, BrF, formation or from the kinetics of Br consumption in excess of F 2 : k 1 = (4.66 ± 0.93) × 10 −11 exp(−(4584 ± 86)/ T ) cm 3 molecule −1 s −1 at T = 300–940 K. The rate constant of the reaction F 2 + Br 2 → products (2), k 2 = (9.23 ± 2.68) × 10 −11 exp(−(8373 ± 194)/ T ) cm 3 molecule −1 s −1 , was determined in the temperature range 500–958 K by monitoring both reaction product (FBr) formation and F 2 consumption kinetics in excess of Br 2 . The results of the experimental measurements of the yield of FBr (1.02 ± 0.07 at T = 960 K) combined with thermochemical calculations indicate that F+Br 2 F forming channel of reaction (2) is probably the dominant one, at least, at highest temperature of the study.