Silicon chemistry in zero to three dimensions: from dichlorosilylene to silafullerane

Abstract

Silylenes and silanides, prominent Si(ii) species, are not only interesting in their own right, but also constitute important building blocks in oligosilane and organosilane chemistry. The past decade has witnessed tremendous advances in the understanding of the ambiphilic behavior of silylenes and the nucleophilic properties of silanides, as well as the mutual relationships between both species. Especially the readily available SiCl/[SiCl] system is intriguing, because it features highly functionalized silicon centers, amenable to late-stage modifications. Moreover, SiCl and [SiCl] are interconvertible by mere chloride association/dissociation. This Feature Article first provides a brief introduction to isolable (functionalized) silylenes and silanides and then focusses on the SiCl/[SiCl] couple. Classical high-temperature protocols for the generation of SiCl are juxtaposed with convenient recent solution phase methods that provide access to RN-SiCl and [SiCl]via deprotonation of HSiCl or the amine-/chloride-induced disproportionation of SiCl. We give a comprehensive overview of key mechanistic issues and highlight the utility of RN-SiCl and [SiCl] for the synthesis of open-chain and cyclic oligosilanes as well as nanoscale, fullerene-type silicon clusters.

Pentafluoroethylated Compounds of Silicon, Germanium and Tin

“…Since the fundamentalw ork of Lappert et al in the 1970'st he stabilization of monomeric germylenes and stannylenes,t he heavier homologueso fc arbenes,w as achieved by bulky substituentsw hereby oligomerization could be avoided. [66] An electronic stabilization of ER 2 (E = Ge, Sn) has been rarely realized and is mostly combined with bulky substituents. [67] According to Bent's rule the introduction of electron-withdrawing groups induces ahigher p-orbital character in the binding orbital which concomitantly leads to ah igher s-orbital character in the orbital occupied by the lone pairo fe lectrons and therefore to al ess marked oligomerization tendency.…”

f-Element silicon and heavy tetrel chemistry

“…The chemistry of both of these silicon reagent families have previously been reviewed. [34][35][36] Examples of f-element silylene adducts are relatively scarce, and f-element silanide complexes are dominated by the tris-(trimethylsilyl)silanide anion, ({Si(SiMe 3 ) 3 }) À , frequently referred to as hypersilanide, and its derivatives.…”

Halide‐Ion Diadducts of Perhalogenated Cyclopenta‐ and Cyclohexasilanes

“…Perhalogenated oligosilanes are of great technological importance, because they find use in the synthesis of silicon‐containing polymers and also as precursor molecules for the deposition of amorphous or crystalline silicon . A deeper understanding of the intrinsic properties of perhalogenated oligosilanes can best be gained by investigating samples of monodisperse, cyclic species to avoid spurious chain‐length and end‐group effects.…”