Formation of a 1,4-Diamino-2,3-disila-1,3-butadiene Derivative

A 1,4-diamino-2,3-disila-1,3-butadiene derivative of composition (Me2-cAAC)2(Si2Cl2) (Me2-cAAC = :C­(CMe2)2(CH2)­N-2,6-iPr2C6H3) was synthesized by reduction of the Me2-cAAC:SiCl4 adduct with KC8. This compound is stable at 0 °C for 3 months in an inert atmosphere. Theoretical studies reveal that the silicon atoms exhibit pyramidal coordination, where the Cl–Si–Si–Cl dihedral angle is twisted by 43.3° (calcd 45.9°). The two silicon–carbon bonds are intermediates between single and double Si–C bonds due to twisting of the C–Si–Si–C dihedral angle (163.6°).