The free cyclohexasilane Si6Cl12 (1) was obtained in 66% yield from the corresponding Cl- diadduct [nBu(4)N](2)[1.2Cl] and AlCl3 in C6H6. The substituted cyclohexasilane 1,1-(Cl3Si)(2)Si6Cl10 (2), however, cannot be liberated from [nBu(4)N](2)[2.2Cl] under comparable reaction conditions. Instead, a mixture of several products was obtained, from which the oligosilane Si19Cl36 (3) crystallized in low yields. X-ray crystallography revealed 3 to consist of two Si-5 rings, bridged by one silicon atom. Compound 1 possesses Lewis acidic sites above and below the ring centroid. Competition experiments reveal that their corresponding acid strengths are comparable to that of BCl3. The reaction of 1 with 6 equiv of 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene (Idipp) leads to a complete breakdown of the cyclic scaffold and furnishes the dichlorosilylene adduct Idipp-SiCl2.