SiBr₂(Idipp): A Stable N‐Heterocyclic Carbene Adduct of Dibromosilylene

Abstract

Silylene with a carbene carabiner: The synthesis, structure, and some reactions of a stable carbene adduct of dibromosilylene, SiBr2(Idipp) (see picture; Idipp=1,3‐bis(2,6‐diisopropylphenyl)‐ imidazol‐2‐ylidene), are described. SiBr2(Idipp) was characterized by X‐ray crystallography, NMR spectroscopy, and theoretical methods.

Stable N‐Heterocyclic Carbene Adducts of Arylchlorosilylenes and Their Germanium Homologues

“…[11] In view of this potential, the isolation of related silicon compounds is expected to have far-reaching consequences in organosilicon chemistry. An advancement in this context is the present report, in which the electronic stabilizing effect of N-heterocyclic carbenes (NHC) [12] was used to obtain the first carbene adducts of arylchlorosilylenes SiArClA C H T U N G T R E N N U N G (Im-Me 4 ) (Ar= C 6 H 3 -2,6-Mes 2 , C 6 H 3 -2,6-Trip 2 ; Im-Me 4 = 1,3,4,5-tetramethyl-A C H T U N G T R E N N U N G imidazol-2-ylidene), which are compared to the homologous germanium compounds.…”

Synthesis and Characterization of N-Heterocyclic Carbene-Coordinated Silicon Compounds Bearing a Fused-Ring Bulky Eind Group

“…The upfield-shifted 29 Si resonance for 3a (δ = −63.3 ppm) suggests the contribution of the canonical form due to the bis(imidazolium) adduct of a silyl anion, whose electronic structure was previously supported by the theoretical calculations of VIIb′ and VIIf [22]. In the 13 C NMR spectrum of 3a in CD3CN, one NHC carbene signal was observed at δ = 162.0 ppm, comparable to those for VIIb (δ = 160.5 ppm), VIIb′ (δ = 162.4 ppm), and VIIf (δ = 160.4 ppm) [22].…”

“…Nuclear magnetic resonance (NMR) measurements were carried out using a JEOL ECS-400 spectrometer (399.8 MHz for 1 H, 100.5 MHz for 13 29 Si NMR spectra. The absolute values of the coupling constants are given in Hertz (Hz) regardless of their signs.…”

“…Among them, the coordination chemistry of highly-reactive halosilylenes, i.e., halogen-substituted divalent Si(II) species, have attracted a lot of attention as potentially useful precursors for the construction of a wide range of silicon-containing compounds [12][13][14][15][16][17]. Figure 1 shows recent examples of coordination-stabilized arylhalosilylenes and their derivatives [18][19][20][21][22][23][24].…”

S–H Bond Activation in Hydrogen Sulfide by NHC-Stabilized Silyliumylidene Ions

“…Key to these developments have been the usage of suitable synthetic methodologies in combination with thermodynamic and kinetic stabilization by appropriately chosen ligands. In particular, for the heavier carbon analogue silicon, a plethora of studies reported new low-valent compounds in recent years [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] and the chemistry of silylene base adducts has already been carefully developed [14,[26][27][28][29][30][31][32][33][34][35][36]. Before these findings, silyliumylidene ions, cationic Si(II) species were found to be promising as similar versatile Lewis amphiphiles [37,38].…”