Structure and Solution Reactivity of (Triethylsilylium)triethylsilane Cations

Abstract

Reaction of triphenylmethylium tetrakis-(pentafluorophenyl)borate, [Ph 3 C][B(C 6 F 5 ) 4 ], with excess neat triethylsilane affords triethylsilylium(triethylsilane) tetrakis(pentafluorophenyl)borate, [(Et 3 Si) 2 (μ-H)][B(C 6 F 5 ) 4 ](1), identified by X-ray crystallography. In chlorobenzene and fluorobenzene, 1 is observed in solution. When 1 is dissolved in benzene or toluene, the evolved gas was shown to be hydrogen. Isotope labeling experiments demonstrate that the hydrogen arises from the reaction of Et 3 SiH with the silylium complex of the arene solvent.

Synthesis and Properties of the Weakly Coordinating Anion [Me3NB12Cl11]−

“…The Et 3 Si(Me 3 NB 12 Cl 11 ) part of the structure is almost identical to the above discussed structure of solely Et 3 Si(Me 3 NB 12 Cl 11 ). In the [(Et 3 Si) 2 H] + cation the Si2⋅⋅⋅Si3 distance (319.5(2) pm) as well as the sum of C‐Si‐C angles around Si2 (∑(C‐Si2‐C): 346.2(5)°)38 are similar to those obtained for [(Et 3 Si) 2 H][B(C 6 F 5 ) 4 ] (Si⋅⋅⋅Si: 321.7(9) pm, ∑(C‐Si‐C): 347.4(4)° and 349.2(4)°) 36…”

“…(Si···Si: 321.7(9) pm, AE(C-Si-C): 347.4(4)8 and 349.2(4)8). [36] The isolation of crystals containing the hydrogen-bridged [(Et 3 Si) 2 H] + cation and the [Et 3 Si] + cation is in agreement with the observation of several cationic silylium compounds in the 1 H and 29 Si NMR spectra and with the observation of the n as (Si-H-Si) vibration in the solid reaction product.…”

A Dysprosium Metallocene Single‐Molecule Magnet Functioning at the Axial Limit

“…Halide abstraction from a hard lanthanide cation should require a highly electrophilic reagent, and the readily accessible triethylsilyliumcontaining salt [(Et3Si)2(-H)][B(C6F5)4] was deemed to be an excellent candidate. [12] We reasoned that the driving force for halide abstraction would be greater with X = chloride, hence our initial target compound was [(Cp ttt )2DyCl] (1Dy) (Scheme 1). Compound 1Dy was synthesized by refluxing [DyCl3(THF)3.5] with two equivalents of KCp ttt in toluene for 72 hours.…”

Efficient and Selective Hydrosilylation of Secondary and Tertiary Amides Catalyzed by an Iridium(III) Metallacycle: Development and Mechanistic Investigation

“…Our analysis of the computed thermochemistry suggested clearly that the necessary dechlorination of precatalyst 3 to yield the putative electron‐deficient cationic intermediate 10 b results from a reaction with an in situ produced form of a stabilized silylium cation generated by the reaction of the tritylium cation with the silane reagent . For instance, the reaction of Et 3 SiH with Ph 3 C + is expected to produce triphenylmethane and [Et 3 Si−H−SiEt 3 ] + according to Heinekey et al . with a Gibbs enthalpy of −9 kcal mol −1 according to our DFT‐D computations (Schemes and a).…”