Magnesium (mono)cyanide (MgCN) was identified in IRC +10216 in 1995 by Ziurys et al. using the 12 meter telescope at Kitt Peak near Tuscon, Arizona. There has apparently been no subsequent work confirming the initial detection, in which three consecutive pairs of rotational transitions were found to match the prior laboratory spectrum reported by Anderson, Steimle, & Ziurys.

MgCN is slightly less stable than the isocyanic isomer MgNC, by less than 2 kcal/mol at the RCCSD(T)/aug-cc-pVTZ level of theory. MgNC was observed in IRC +10216 about a decade prior to the MgCN identification. The bonding between Mg and CN in both MgCN and MgNC is very ionic, resulting in large dipole moments of about 5.3 D for both specis at the level of theory cited above.