Cyanophosphaethyne (N≡C–C≡P) was tentatively detected toward IRC +10216 (CW Leo) by Agúndez, Cernicharo, & Guélin in a study published in 2014 based on observations made with the IRAM 30m telescope. The detection utilized the rotatational spectrum and constants for NCCP measured by Bizzochi and co-workers from 2001. The identification has not yet been confirmed with further observations and analysis or detected in other sources.

If cyanophosphaethyne seems like an overlong name for a molecule containing just four atoms, the preferred name of phosphanylidyneacetonitrile is worse, especially since cyanophosphaethyne is a close relative of a molecule with a very compact name, cyanogen, N≡C–C≡N. However, substituting one of the N atoms in cyanogen with P to form cyanophosphaethyne changes a molecule with no dipole moment that consequently does not have a pure rotational spectrum and thus has yet to be detected into one with a dipole moment of ~3.4 D that has a strong rotational spectrum. Cyanophosphaethyne joins the pantheon of detected molecules containing the cyano (–CN) or isocyano (–NC) groups.