Tetrakis(di-tert-butylmethylsilyl)distannene and its anion radical

Tetrakis(di-tert-butylmethylsilyl)distannene 1 was synthesized by the coupling reaction of tBu2MeSiNa with SnCl2-diox in THF and isolated as dark-green crystals. X-ray analysis of 1 showed the shortest Sn=Sn double bond (2.6683(10) A) among all acyclic distannenes, an almost planar geometry around the Sn atoms, and a highly twisted Sn=Sn double bond. The reaction of distannene 1 with CCl4 produced 1,2-dichlorodistannane 2, implying that 1 does not dissociate into stannylenes, both in the solid state and in solution. The one-electron reduction of 1 with potassium furnished the corresponding distannene anion radical 3, the stable ion radical of the heavy alkene analogues, which has been fully characterized by X-ray crystallography and ESR spectroscopy.