One-Electron-Mediated Rearrangements of 2,3-Disiladicarbene

A disiladicarbene,
(Cy-cAAC)2Si2 (2), was synthesized
by reduction of Cy-cAAC:SiCl4 adduct
with KC8. The dark-colored compound 2 is stable
at room temperature for a year under an inert atmosphere. Moreover,
it is stable up to 190 °C and also can be characterized by electron
ionization mass spectrometry. Theoretical and Raman studies reveal
the existence of a SiSi double bond with a partial double
bond between each carbene carbon atom and silicon atom. Cyclic voltammetry
suggests that 2 can quasi-reversibly accept an electron
to produce a very reactive radical anion, 2•–, as an intermediate species. Thus,
reduction of 2 with potassium metal at room temperature
led to the isolation of an isomeric neutral rearranged product and
an anionic dimer of a potassium salt via the formation of 2•–.