Isotopologue

Not to be confused with isotopomers.

Isotopologues are molecules that differ only in their isotopic composition. Simply, the isotopologue of a chemical species has at least one atom with a different number of neutrons than the parent.

An example is water, where some of its hydrogen-related isotopologues are: "light water" (HOH or H2O), "semi-heavy water" with the deuterium isotope in equal proportion to protium (HDO or 1H2HO), "heavy water" with two deuterium isotopes of hydrogen per molecule (D2O or 2H2O), and "super-heavy water" or tritiated water (T2O or 3H2O), where the hydrogen atoms are replaced with tritium isotopes. Oxygen-related isotopologues of water include the commonly available form of heavy-oxygen water (H218O) and the more difficult to separate version with the 17O isotope. Both elements may be replaced by isotopes, for example in the doubly labeled water isotopologue D218O.

Isotopologues may be used for nuclear magnetic resonance experiments, where deuterated solvents do not interfere with the solutes' 1H signals, and in investigations of the kinetic isotope effect.

See also

References

IUPAC, Compendium of Chemical Terminology, 2nd ed. (the "Gold Book") (1997). Online corrected version:  (1994) "Isotopologue".

External links