This prefix is now rejected. It has been used in the past, especially in cyclic systems, to name carbenes, e.g. 'carbenacycloheptane', now cycloheptylidene.
Source:
PAC, 1995, 67, 1307
(Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations 1995))
on page 1324
Transformed and rewritten from PDF version (entry
http://www.iupac.org/goldbook/C00805.pdf)
by: Miloslav Nic, Jiri Jirat, Bedrich Kosata, ICT Prague, Czech Republic
