A reinvestigation of the laser-initiated chlorine/hydrogen bromide chain reaction: absolute rate constants and the v = 2/v = 1 ratio from chlorine atom + hydrogen bromide .fwdarw. hydrogen chloride(v) + bromine atom

1987 ◽  
Vol 91 (13) ◽  
pp. 3543-3550 ◽  
Author(s):  
David A. Dolson ◽  
Stephen R. Leone
1983 ◽  
Vol 61 (9) ◽  
pp. 2037-2043 ◽  
Author(s):  
A. Baignée ◽  
J. H. B. Chenier ◽  
J. A. Howard

The major initial products of the self-reaction of α-tetralylperoxyls (C10H11O2•) in chlorobenzene at 303–353 K are equal concentrations of α-tetralol and α-tetralone in ~90% yield based on the number of initiating radicals. These yields are consistent with the non-radical (Russell) mechanism for self-reaction. Low concentrations of bis(α-tetralyl) peroxide are produced, indicating that there is a small but detectable free-radical contribution towards termination. C10H11O2• undergoes β-scission in this temperature range but steady-state concentrations of C10H11• are too low to influence the termination rate constant 2kt, or react with C10H11O2• to give (C10H11O2. α-Tetralol to α-tetralone ratios and total yields of these products are significantly less than 1 and 100%, respectively, in methanol and acetonitrile. Formaldehyde is produced in methanol indicating the involvement of α-hydroxymethylperoxyls, derived from the solvent, in termination. There is no evidence for a chain reaction or a zwitterion intermediate for self-reaction of C10H11O2• in solution.


1971 ◽  
Vol 24 (10) ◽  
pp. 2031
Author(s):  
DA Kairaitis ◽  
VR Stimson

The gas-phase decomposition of ethyl bromide at 423� in the presence of both ethylene and hydrogen bromide has been investigated. These additives, which are also the products, each influence the rate strongly but in opposite ways. The variation of initial rate with reactant pressure is given by (P in cm) ������������� k1 (min-1) = 15.2x10-3+19.5x10-3(PEtBrPHBr/PEne)1/2 This has been interpreted in terms of a unimolecular decomposition together with a bromine atom carried chain reaction with simple steps that involve the products. Some insight into the unaccompanied decomposition has been gained. Some remarks about the role of olefinic inhibitors in reactions producing hydrogen bromide have been made.


1967 ◽  
Vol 20 (6) ◽  
pp. 1143 ◽  
Author(s):  
RL Failes ◽  
VR Stimson

Hydrogen iodide catalyses the decomposition of isopropanol into propene and water at 356 to 457�, viz. �������������������������� i-C3H7OH+HI → C3H6+H2O+HI This is followed by the faster reactions �������������������������� C3H6+HI → i-C3H7I ����� ��������������������i-C3H7I+HI → C3H8+I2������������������������ i-C3H7OH+I2 → (CH3)2CO+2HI The rates of the initial reaction fit the Arrhenius equation ����������������� k2 = 1012.24 exp(-31900/RT) sec-1 ml mole-1 and it is believed to be homogeneous and molecular. It is faster than the corresponding reactions with hydrogen chloride and hydrogen bromide in the ratios 100 : 1 and 5 : 1, respectively. For the overall reaction the amounts of the products formed to 70% reaction, computed with the use of rate constants of the individual reactions, agree well with the amounts found by analysis.


1970 ◽  
Vol 48 (14) ◽  
pp. 2165-2172 ◽  
Author(s):  
J. A. Howard ◽  
S. Korcek

Absolute propagation and termination rate constants have been measured for the liquid phase autoxidation of some α-substituted toluenes at 30 °C. Rate constants for reaction of α-substituted toluenes with their own peroxy radical and with the t-butylperoxy radical have been compared. It would appear that the reactivity of an α-substituted benzylperoxy radical depends on the nature of the α-substituent.Reactivities of α-substituted toluenes towards the t-butylperoxy radical, the bromine atom, and the phenyl radical have been compared.


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