## Wikipedia - Effet isotopique cinétique (fr) kinetic isotope effect

https://doi.org/10.1351/goldbook.K03405
The effect of isotopic substitution on a @[email protected] is referred to as a kinetic @[email protected] For example, in the reaction:
K03405-1.png
the effect of isotopic substitution in reactant A is expressed as the ratio of rate constants $$\frac{k^{\text{l}}}{k^{\text{h}}}$$, where the superscripts $$\text{l}$$ and $$\text{h}$$ represent reactions in which the molecules A contain the light and heavy @[email protected], respectively. Within the framework of @[email protected] in which the reaction is rewritten as:
K03405-2.png
and with neglect of isotopic mass on @[email protected] and the @[email protected], $$\frac{k^{\text{l}}}{k^{\text{h}}}$$ can be regarded as if it were the @[email protected] for an @[email protected] reaction between the @[email protected] [TS] and the @[email protected] reactant A, and calculated from their vibrational frequencies as in the case of a @[email protected] Isotope effects like the above, involving a direct or indirect comparison of the rates of reaction of @[email protected], are called '@[email protected]', in contrast to @[email protected], in which a single substrate reacts to produce a non-statistical distribution of @[email protected] product molecules.