Reductions of bulky alkynyl-substituted dihalosilanes, BbtSiX(2)(C[triple bond]CR) (Bbt = 2,6-bis[bis(trimethylsilyl)methyl]-4-[tris(trimethylsilyl)methyl]phenyl, R = SiMe(3) or Ph groups, X = halogen), with 2.0 equiv. of lithium naphthalenide gave the first stable 1,2-dialkynyl-substituted disilenes, which constituted extended pi-conjugated systems between Si=Si bond and ethynylene units.