Metal complexes of the type RCMLn (M = metal, L = ligand) in which formally a carbyne is coordinated to a metal, e.g.
M03861.png
Source: PAC, 1995, 67, 1307. (Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations 1995)) on page 1349 [Terms] [Paper]