( t Bu2MeSi)2SnSn(SiMe t Bu2)2:  A Distannene with a >SnSn< Double Bond That Is Stable Both in the Solid State and in Solution

• Published in: Journal of the American Chemical Society Vol. 128; no. 35; pp. 11643 - 11651
• Main Authors: Lee, Vladimir Ya, Fukawa, Tomohide, Nakamoto, Masaaki, Sekiguchi, Akira, Tumanskii, Boris L, Karni, Miriam, Apeloig, Yitzhak
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 06.09.2006
• Subjects: Chemistry; Exact sciences and technology; General and physical chemistry; Chemical solution; Acetylenic compound; Potassium compound; Tin II Chlorides; Carbon tetrachloride; EPR spectrometry; NMR spectrometry; Tetrahydrofurane; Planar molecule; Chemical reduction; Solid state; Alkene; Organic free radical; Radical anion; Chemical reactivity; Spectrophotometry; Chemical synthesis; Ethylenic compound; Low temperature; Crystalline structure
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/ja063322x

( t Bu2MeSi)2SnSn(SiMe t Bu2)2 1, prepared by the reaction of t Bu2MeSiNa with SnCl2-diox in THF and isolated as dark-green crystals, represents the first example of acyclic distannene with a SnSn double bond that is stable both in the crystalline form and in solution. This was proved by the crystal and NMR spectral data of 1. Distannene 1 has these peculiar structural features:  a shortest among all acyclic distannenes SnSn double bond of 2.6683(10) Å, a nearly planar geometry around both Sn atoms, and a highly twisted SnSn double bond. The reactions of 1 toward carbon tetrachloride and phenylacetylene also correspond to the reactivity anticipated for the SnSn double bond. The one-electron reduction of 1 with potassium produced the distannene anion radical, the heavy analogue of alkene ion radicals, for which the particular crystal structure and low-temperature EPR behavior are also discussed.