Chlorine-catalysed Pyrolysis of 1,2-Dichloroethane. Part 2.-Unimolecular Decomposition of the 1,2-Dichloroethyl Radical and its Reverse Reaction

DOI: 10.1039/f19827800677

Source and publish data:

Journal of the Chemical Society, Faraday Transactions 1: Physical Chemistry in Condensed Phases p. 677 - 694 (1982)

Update date:2022-08-29

Topics:

Authors:

Ashmore, Philip G.

Owen, Anthony J.

Robinson, Peter J.

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Article abstract of DOI:10.1039/f19827800677

Fall-off curves for the unimolecular rate constant k₂ of the reaction have been calculated by the Forst and RRKM methods and compared with the experimental results reported in Part 1 and by Huybrechts et al.The Forst calculations can be fitted to the Part 1 results, but then predict K₂^(infinite) values that lie below the experimental results of Huybrechts et al. which refer to lower temperatures and higher pressures.In contrast RRKM calculations using higher Arrhenius parameters give fall-off curves that are compatible with all available experimental data.The preferred RRKM models without allowance for the centrifugal effect have E₂^(infinite) ca 19.6 kcal/mol (82 kJ 1/mol) and A₂^(infinite) ca 1E14.0 s^-1.When a reasonable centrifugal effect is allowed for the early transition state (I⁺/I ca 2) the preferred models have E² ca 20.0 kcal 1/mol (84 kJ 1/mol) and A₂^(infinite) ca 1E14.3 s^-1.Our experimental evaluations of k^(p)_-2 are used in conjunction with earlier experimental results and RRKM-based calculations for the reverse reaction to evaluate A_-2^(infinite) and E_-2^(infinite).