Knowledge Bank

Silene has been produced in the gas phase by vacuum flash pyrolysis of 5-6-bis(trifluoromethyl)-2-silabicyclo[2.2.2]octa-5,7-diene (SBO) at $600\circ Ca$. Its rotational spectrum corresponding to a slightly asymenlzie top was observed in a liquid nitrogen cooled cell when argon was used as carrier gas. The assignment of $H2CSiH2$ lines has been made by comparing experimental molecular constants with ab initio predicted values from Breidung and $Thielb$. The observation of several lines belonging to the $\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}9/Si$ isotopic species in natural abundance confirmed unambiguously this identification. This work led to the first high resolution spectroscopic results for silene. Study of different isotopomers is in progress and will give an experimental structure of this compound.