Redox Noninnocent Monoatomic Silicon(0) Complex (“Silylone”): Its One-Electron-Reduction Induces an Intramolecular One-Electron-Oxidation of Silicon(0) to Silicon(I)

Abstract

A monatomic zerovalent silicon(0) complex (“silylone”) stabilized by the chelating bis­(silylenyl)-ortho-carborane ligand, 1,2-(LSi)2-1,2-C2B10H10 [L = PhC­(NtBu)2], has been synthesized from the redox reaction of the dipotassium bis­(silylenyl)-nido-carboranate salt, 1,2-(LSi)2-1,2-C2B10H10K2, and NHC-SiCl2 (NHC = {[HCN­(2,6-iPr2C6H3)]2C:}). Markedly different from previous examples, this silylone undergoes reduction due to the closo-C2B10 cluster backbone, which is prone to accept up to two electrons to form the cage-opened dianionic nido-C2B10 cluster core. Surprisingly, the closo-C2B10 core of the silylone consumes only one molar equiv of potassium naphthalenide, in addition, one electron is intramolecularly transferred from the Si0 atom to the C2B10 core to form an elusive bis­(silylene)-stabilized SiI radical cation which undergoes homocoupling to the corresponding isolable dicationic SiI–SiI complex.

Bis(silylene)‐Stabilized Monovalent Nitrogen Complexes

“…L (L = NHC or NHSi, E = Si, Ge). [24][25][26][27] The ortho-carboranebased bis(silylene) 1 (Scheme 3) with a relatively short Si•••Si distance of ca.3.3 , reported by us in 2016, [28] is reactive towards CO and isocyanides but also suitable as a strong chelating Lewis donor scaffold in coordination chemistry with respect to transition-metals and main group elements. [29][30][31][32] With 1 in hand, we developed very recently the bis(NHSi)supported Si 0 complex C [26b] (Scheme 1) and envisioned that bis(NHSi)-supported N I complexes could be achievable.…”

Bis(silylene)‐Stabilized Monovalent Nitrogen Complexes

“…The ortho ‐carborane‐based bis(silylene) 1 (Scheme 3) with a relatively short Si⋅⋅⋅Si distance of ca.3.3 Å, reported by us in 2016, [28] is reactive towards CO and isocyanides but also suitable as a strong chelating Lewis donor scaffold in coordination chemistry with respect to transition‐metals and main group elements [29–32] . With 1 in hand, we developed very recently the bis(NHSi)‐supported Si 0 complex C [26b] (Scheme 1) and envisioned that bis(NHSi)‐supported N I complexes could be achievable. Since NHSis have a stronger donor ability than NHCs, [33] such complexes could, in turn, serve as more nucleophilic N I ligands toward metals.…”

Changing the Reactivity of Zero‐ and Mono‐Valent Germanium with a Redox Non‐Innocent Bis(silylenyl)carborane Ligand

“…The electronic structure of 4 closely resembles that of the aforementioned Si 2 homologue (Figure S20). [22] To investigate the one-electron oxidation, 3 was allowed to react with one molar equiv of [Cp 2 Fe][B{C 6 H 3 (CF 3 ) 2 } 4 ] in THF at room temperature, which led to the isolation of a new [Ge I -Ge I ] coupling compound 5 as an orange solid in 92 % yield (Scheme 2). This product is also insoluble in diethyl ether, but well soluble in THF.…”