The First Planar, Not Twisted, Distannene − A Structural Alkene Analog. Synthesis, Isolation and X‐ray Crystallography Characterization

Abstract

AbstractThe tetrasilyl‐substituted distannene, (tBu2HSi)2Sn=Sn(SiHtBu2)2 6, was synthesized by mild thermolysis (70 °C in hexane) of tris(di‐tert‐butyl‐hydridosilyl)stannane 4. The X‐ray crystallography structure of 6 reveals the following unusual structural properties: a planar geometry around both Sn atoms (Σ∡Sn=359.87°), a non‐twisted Sn=Sn double bond, and the shortest Sn=Sn double bond of 2.599 Å among all acyclic distannenes. Thus, compound 6 is the first reported distannene having a structure closely analogous to a classic alkene. Reactions of 6 with CCl4 or with 2,3‐dimethylbuta‐1,3‐diene to produce 1,2‐dichlorodistannane 9 and the [2+4] cycloadduct 10, respectively, are characteristic for a Sn=Sn double bond.