The optical spectrum of HCSi

A new emission band system has been observed in the gas phase at around 850 nm. This system correlates with absorption bands previously measured in a neon matrix and assigned to a triplet electronic transition of SiC. However, the gas phase bands display a clear doublet structure. Preliminary molecular parameters resulting from the rotational analysis of the (000) - (000) band coincide with the expected values obtained by a recently published ab initio calculation carried out on the HCSi radical. We conclude that both the gas phase and the neon matrix spectra originate from the HCSi radical which is here identified for the first time.