Iron monocyanide (FeCN) was detected in IRC +10216 by
Zack et al. and reported in 2011. The 12 m telescope
at the Arizona Radio Observatory was used to make the observations. There
has been some debate about the ground state of FeCN, which stems from the fact that there are multiple quartet and
sextet states with similar energies. The experimental study of
Flory & Ziurys found the ground state to be a quartet, while
theoretical studies such as those by
DeYonker et al. and
Hirano et al. find that the sextet state is more stable.
A number of other cyanide species have been observed in interstellar or circumstellar media,
cyano methyl radical,
silicon cyanide, cyanoallene,
amino acetonitrile, n-propyl cyanide, and potassium cyanide.