Silicon monocyanide (SiCN) was detected by
Guélin et al. in 2000 toward
CW Leo (IRC +10216) using the
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.