cumulenes in which one or more carbon atoms of the cumulative bond system have been replaced by heteroatoms. E.g. O=C=C=C=O
, but not CH2=C=O
, ketene, nor O=C=O
, carbon dioxide, which are heteroallenes.
PAC, 1995, 67, 1307. 'Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations 1995)' on page 1340 (https://doi.org/10.1351/pac199567081307)