Talk:Isotopologue

Not isotopic isomer
Isotopomer is a contraction of isotopic isomer (check IUPAC). Thus how can an isotopologue (a distinctly different beast) be an isotopic isomer? ;-) Check the definition of an isomer.  Isotopologues are not even isomers.  150.203.35.113 (talk) 02:06, 20 May 2008 (UTC)
 * I don't see anything in the article that contradicts what you are saying. DMacks (talk) 05:34, 20 May 2008 (UTC) Nevermind...didn't see that you had corrected it:) DMacks (talk) 05:36, 20 May 2008 (UTC)

Isotopologues and isotopomers
There is potential for confusion between isotopologues and isotopomers. See Footnote 3 in Rothman http://dx.doi.org/10.1016/j.jqsrt.2004.10.008 reproduced below:

An isotopologue is a molecular twin, as it were, that differs from the original molecule in the isotopic composition (number of isotopic substitutions) only; for example, 13CH4 and 12CH3D are isotopologues of 12CH4. An isotopomer (a contraction of ‘isotopic isomer’), on the other hand, has the same number of each of the isotopic atoms but differing in their orientation within the molecular structure (giving rise to different spectra), for example 16O18O16Oisan isotopomer of 16O16O18O and so is 14N15NO of 15N14NO.

Concept not completely defined
There seems to be ambiguity in the definition given in the article. It says that the three isotopomers of monodeuterated ethanol (––OH, ––OH, and ––OD) are the same isotopologue, okay. But what about –O–? Is it the same isotopologue, or a diferent one? --Jorge Stolfi (talk) 17:49, 23 August 2020 (UTC)
 * The lead says "They have the same chemical formula and bonding arrangement of atoms, but at least one atom has a different number of neutrons than the parent.". The dimethyl ether do not have the same bonding arrangement as ethanol, i.e. its a different functional isomer. Christian75 (talk) 18:50, 23 August 2020 (UTC)