nitrilium ions

https://doi.org/10.1351/goldbook.N04156
Cations derived formally by @A00512@ of one @H02904@ to the nitrogen atom of a nitrile and hydrocarbyl derivatives thereof. E.g. N04156.png benzonitrilium.
Source:
PAC, 1995, 67, 1307. (Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations 1995)) on page 1351 [Terms] [Paper]