A chemical reaction in which the reactant and product chemical species are chemically
identical but have different isotopic composition. In such a reaction the isotope
distribution tends towards equilibrium (as expressed by fractionation factors) as
a result of transfers of isotopically different atoms or groups. For example:
Source:
PAC, 1994, 66, 1077
(Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994))
on page 1132
PAC, 1994, 66, 2513
(Nomenclature for radioanalytical chemistry (IUPAC Recommendations 1994))
on page 2521