The new type of the twelve- to twenty-four-membered rings [(i-Pr)(2)Si(i-Pr)(2)SiCequivalent toCCequivalent toC](n) (1, n = 2; 2, n = 3; 3, n = 4) were synthesized and the molecular structures of 1 and 2 were analyzed by X-ray crystallography. The compounds show unusual electronic properties due to the interaction of the Cequivalent toC pi orbitals with the Si-Si sigma bonds.