The cyanomethyl radical (CH₂CN) was initially reported by Irvine & coworkers in 1988 in two of the best charactarized molecular clouds, TMC-1 and Sgr B2, based upon measurements collected with four telescopes: the decommisioned 14 m antenna at the Five College Radio Astronomy Observatory, the 43 m antenna at NRAO's Green Bank facility, the 20 m antenna at Onsala Space Observatory, and the 45 m antenna at Nobeyama Radio Observatory. The observations utilized experimental data by Saito & coworkers. The spectra was refined in a 2004 paper by Ozeki and coworkers. The first detection of CH₂CN in a circumstellar source, IRC +10216, was reported by Agúndez & coworkers in 2008.

Cyanomethyl radical can be formed by removing a hydrogen atom from another observed astromolecule, methyl cyanide, which yields a planar radical with the unpaired electron on the central carbon atom as shown to the right. It has been suggested by Cordiner & Sarre that another related species, CH2CN–, might be the carrier for one of the many poorly characterized diffuse interstellar bands.