isocyanides

https://doi.org/10.1351/goldbook.I03270
The @I03289@ HN+≡C of hydrocyanic acid, HC≡N, and its @H02891@ derivatives RNC (RN+≡C).
Source:
PAC, 1995, 67, 1307. (Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations 1995)) on page 1344 [Terms] [Paper]