The electrically neutral species H2C:
and its derivatives, in which the carbon is covalently bonded to two univalent groups of any kind or a divalent group and bears two nonbonding electrons, which may be spin-paired (singlet state)
or spin-non-paired (triplet state).
In systematic name formation, carbene is the name of the parent hydride :CH2
hence, the name dichlorocarbene for :CCl2
. However, names for acyclic and cyclic hydrocarbons containing one or more divalent carbon atoms are derived from the name of the corresponding all-λ4-hydrocarbon using the suffix -ylidene. E.g. prop-2-en-1-ylidene, H2C=CHCH:
Subclasses of carbenes include acyl carbenes C00806-2.png
, imidoyl carbenes, C00806-3.png
and vinyl carbenes.
PAC, 1995, 67, 1307. 'Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations 1995)' on page 1324 (https://doi.org/10.1351/pac199567081307)