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

A disiladicarbene, (Cy-cAAC)(2)Si-2 (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 degrees 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(circle-), 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(circle-).