A 1,4-diamino-2,3-disila-1,3-butadiene derivative of composition (Me 2-cAAC)2(Si2Cl2) (Me 2-cAAC =:C(CMe2)2(CH2)N-2,6-iPr 2C6H3) 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). © 2013 American Chemical Society.