anti-2,2,3,3,6,6,7,7,10,10,11,11,14,14,15,15-Hexadeca-methyl-2,3,6,7,10,11,14,15-octa-silapenta-cyclo-[10.4.2.2(4,9).0(5,8).0(13,16)]icosa-1(17),4,8,12(18),13(16),19-hexa-ene.

The title compound, C28H52Si8, was synthesized by condensation of two mol-ecules of 1,2,3,4-tetra-kis-(chloro-dimethyl-sil-yl)benzene with lithium. The 3,4-disila-1,2-benzocyclo-butene rings in the centrosymmetric molecule are bridged by 1,1,2,2-tetra-methyl-disilanylene chains with an anti conformation. The benzene rings are deformed by fusion with a 3,4-disilacyclo-butene ring resulting in a slight boat conformation.

An organosilicon cluster with an octasilacuneane core: a missing silicon cage motif.

Cagey silicon: A silicon cluster, consisting of sixteen silicon atoms and composed of an octasilacuneane core (red, see picture) fused with cyclotetrasilanes (orange), was synthesized by reductive tetramerization of tetrachlorocyclotetrasilane. Analytical and theoretical studies reveal the unique structural and electronic features of this organosilicon cluster.