Silicon monocyanide (SiCN) was detected by Guélin et al. in 2000 toward CW Leo (IRC +10216) using the IRAM 30m telescope. The rotational spectra of SiCN was reported by Apponi et al in 2000, which was followed in 2001 by a second study by McCarthy et al. The detection has evidently not been confirmed to date.

Silicon monoisocyanide (SiNC) was discovered several years after SiCN was identified, in 2004. SiCN is more stable than SiNC, but only by a very small degree. SiCN also has a large dipole moment, but both compounds have large dipole moments (SiCN, 3.094 D, and SiNC, 2.609 D, at the RCCSD(T)/aug-cc-pV5Z level) due to the strong ionic character of the Si–CN and Si–NC bonds.