Knowledge Bank

The linear singlet chains $SiC2S$, $SiC4S$ and $SiC4S$, as well as the triplet $SiC3S$, have been detected among the products of a laboratory discharge on the basis of high level coupled cluster ab-initio calculations and characterized by Fourier transform microwave spectroscopy. The molecules were generated in a supersonic expansion of diluted mixtures of silane, diacetylene and carbon disulfide in Ne. Their rotational and centrifugal distortion constants were accurately determined, as was the spin-spin coupling constant $\lambda$ for triplet $SiC3S$. The microwave spectra of the $\mathrm{<mrow\; data-mjx-texclass="ORD">29</mrow>}Si$, $\mathrm{<mrow\; data-mjx-texclass="ORD">34</mrow>}S$ and both $\mathrm{<mrow\; data-mjx-texclass="ORD">13</mrow>}C$ isotopic species of $SiC2S$ were measured, allowing a determination of the individual bond lengths. In addition, several satellite lines were observed near the rotational transitions of $SiC2S$, which were identified as belonging to different bending and stretching vibrational excited states.