Isomers having the same number of each isotopic atom but differing in their positions. The term is a contraction of 'isotopic @I03289@'. Isotopomers can be either constitutional isomers (e.g. CH2DCH=O and CH3CD=O) or isotopic @S05984@ [e.g. (R)- and (S)-CH3CHDOH or (Z)- and (E)-CH3CH=CHD].
PAC, 1994, 66, 1077. (Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994)) on page 1132 [Terms] [Paper]
PAC, 1996, 68, 2193. (Basic terminology of stereochemistry (IUPAC Recommendations 1996)) on page 2211 [Terms] [Paper]