The cyanide anion, CN^–, was discovered by Agúndez et al. in 2010 toward IRC +10216 (a source so well-known that a least one stock photograph of it is available). The detection is one of a plethora of detections made with the IRAM 30m telescope over three decades. CN^– was identified via its J = 2–1 and J = 3–2 rotational transitions. While found to be comparably abundant in IRC +10216, the cyanide anion has evidently not been identified in other sources to date. While ambiguous due to the nature of mass spectrometry, CN^– appears to also be present in the atmosphere of Titan, as reported by Desai et al. in 2017.

CN^– is the most recently detected interstellar anions, following the detection of C₆H^– in 2006, C₄H^– in 2007, C₈H^– in 2007, C₃N^– in 2008, and C₅N^– in 2008. The cyanide ion is present in a number of inorganic salts that are quite toxic.