The kinetics of the reactions of methyl radicals with Br₂, Cl₂, and BrCl

Abstract

A general competitive method is described for the study of the kinetics of the reactions of radicals with halogens and interhalogen compounds in the gas phase. The method is applied to the reactionsover the temperature range of 48"-199"C. I t is found that log ( k~/ k 5 ) = log (kJk7) = (-0.042 f 0.060) -(8700 f 1300)/6 where 6 = 2.303 RT Jlmol. Also,There is no correlation between differences in activation energies and differences in enthalpy changes for these reactions, but polar effects may be important in reactions (7) and (8).

A study of the reactions of fluorine with hydrogen and methane in the initiation phase using a miniature tubular reactor

“…The activation energy for our F2 reaction does not follow the trend toward higher values with decreasing molecular weight of the halogen molecule. This can be understood by a correlation of the activation energies with the bond strength of the halogens, as mentioned in [30]. Two further experimental checks were performed on the proposed reaction mechanism.…”

An Experimental Study of the Kinetics of the Reactions of Isopropyl,sec-Butyl, andtert-Butyl Radicals with Molecular Chlorine at Low Pressures (0.5-7.0 Torr) in the Temperature Range 190-480 K

“…Because the corresponding absolute rate coefficients for the molecular oxygen reactions are known , we can compare our results with the results of Tyndall and coworkers. Several studies have been done on the related reactions CH 3 ● + Cl 2 and C 2 H 5 ● + Cl 2 , whose results will also be used in the discussion of reactivity trends.…”

“…The bath gas used in the experiments was helium, and the rate coefficients appeared to be independent of the helium concentrations employed ([2. [4][5][6][7][8][9][10][11][12][13][14] × 10 16 cm −3 ) for all three reactions. The rate coefficients of the reactions can be approximated in the studied temperature range by the following parameterizations: We estimate that the overall uncertainties of the measured rate coefficients are ±20%.…”

Interplay Between Bromine and Iodine in Oxidative Dehydrogenation

“…In addition to Br 2 and I 2 , IBr is also likely present during propane dehydrogenation [Reaction (14)]. It has been shown that the reaction between a radical and an interhalogen molecule XY (ICl, BrCl and IBr) will always favor attack on the less electronegative atom of XY 13. For this reason, 2‐C 3 H 7 I instead of 2‐C 3 H 7 Br is more likely to be formed on reaction of the ⋅CH(CH 3 ) 2 radical with IBr [Reaction (15)]. …”