Cyclic Alkyl(amino) Carbene Stabilized Biradical of Disilicontetrachloride

One and a half decades ago the formation
of Si2Cl4 from the intermediate species SiCl2 was theoretically
predicted to be exothermic. The hypothetical Si2Cl4 has never been experimentally synthesized and isolated. Herein,
we report that the Si2Cl4 species was stabilized
as singlet biradical (Cy-cAAC·)2Si2Cl4 utilizing two cAAC (cyclic alkyl­(amino) carbene). This compound
is stable, isolable, and storable at rt under an inert atmosphere.
The electronic structure and bonding were studied by theoretical calculations
which revealed that the molecule possesses a singlet biradical ground
state with an unpaired electron on each carbene C atom having opposite
spin.