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Talk:Lindemann mechanism

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Cyclopropane example

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Could someone with access to Journal of Chemical Physics verify that the mechanism added to the article on 10 January 2021 is actually proposed in the 1956 paper by McNesby and Gordon? This mechanism is quite strange (even if the third step is balanced by adding an H+) because it involves ionic dissociation and recombination, whereas gas-phase reactions usually involve simple excitation (as in the Lindemann mechanism of this article) or else radical dissociation and recombination (as in chain reactions). In the accessible excerpt of the JCP article we see a chain reaction, but the few lines of text given suggest that this will not actually be the mechanism proposed by the authors. So I think it would be useful to access the rest of the paper (actually only 1 page since the citation says p.582-583) and see what these authors did propose. And perhaps also to find a more recent reference to see what is accepted now for this reaction. Dirac66 (talk) 22:35, 28 January 2021 (UTC)[reply]

I have now found a more credible mechanism in the book Kinetics and Mechanism (3rd edition, 1980) by Moore and Pearson, who present evidence which favors a Lindemann mechanism with a diradical intermediate from a paper by Lin and Laidler:
(CH2)3 ⇌ °CH2–CH2–C°H2
°CH2–CH2–C°H2 → H2C = CH – CH3
Should we replace the ionic mechanism now in the article with this one? Dirac66 (talk) 02:51, 29 January 2021 (UTC)[reply]
Done. Dirac66 (talk) 02:52, 16 February 2021 (UTC)[reply]