28927-31-3

Basic information

• Product Name: Silylium, trimethyl-
• CAS NO: 28927-31-3
• Molecular Formula: C3H9Si
• Molecular Weight: 73.19
• Mol File: 28927-31-3.mol
• Article Data: 3

Chemical Properties

• CAS DataBase Reference: Silylium, trimethyl-(CAS DataBase Reference)
• NIST Chemistry Reference: Silylium, trimethyl-(28927-31-3)
• EPA Substance Registry System: Silylium, trimethyl-(28927-31-3)

Safety Data

• Hazardous Substances Data: 28927-31-3(Hazardous Substances Data)

Upstream product

• 60836-41-1 C₃H₆⁽¹⁺⁾ 
• 1066-54-2 trimethylsilylacetylene 
• 75-76-3 tetramethylsilane 
• 993-07-7 trimethylsilan 
• 429677-33-8 (p-anisyl)phenylmethyl cation 
• 16804-70-9 cumyl cation 
• 72192-21-3 ethylene oxide radical cation 

Downstream Products

• 112146-25-5 (1S,2R)-2-Phenylsulfanyl-2-trimethylsilanyl-cyclopropanecarboxylic acid phenylamide 
• 993-07-7 trimethylsilan 
• 16804-70-9 cumyl cation 
• 121314-44-1 C₁₁H₁₇Si⁽¹⁺⁾ 

Relevant articles and documents

Kinetics of hydride transfer reactions from hydrosilanes to carbenium ions. Substituent effects in silicenium ions

Rates of hydride transfer from hydrosilanes HSiR1R2R3 with widely varying substitution to para-substituted diarylcarbenium ions have been measured in dichloromethane solution. Generally the reactions follow a second-order rate law, -d[Ar2CH+]/dt = k2[Ar2CH+][HSiR1R2R3], and k2 is independent of the degree of ion-pairing and the nature of the counterion (exceptions are reported). The reaction rates are almost independent of solvent polarity. Kinetic isotope effects exclude an SET-type mechanism and are in accord with a polar mechanism with rate-determining formation of silicenium ions. The reactivities of para-substituted aryldimethylsilanes are linearly correlated with σp (ρ = -2.46), not with σp+. In the series H3SiHex, H2SiHex2, HSiHex3, the relative reactivities are 1.00:155:7890, and in the corresponding phenyl series the reactivity increase is much smaller (H3SiPh:H2SiPh2:HSiPh3 = 1.00:17.2:119). As a consequence, trihexylsilane is approximately two orders of magnitude more reactive than triphenylsilane though hexylsilane and phenylsilane show similar reactivities. Tris(trimethylsilyl)silane is just slightly more reactive than trimethylsilane. Replacement of hydrogen by chlorine reduces the reactivity by one order of magnitude. Variation of the electrophilicities of the hydride abstractors does not affect the relative reactivities of the silanes, i.e., constant selectivity (Ritchie-type) relationships are encountered. Correlation equations are given, which permit the calculation of hydride transfer rates from hydrosilanes to any carbenium ion on the basis of pkR+ values or the ethanolysis rate constants of the corresponding alkyl chlorides.

Precise Determination of Stabilities of Primary, Secondary, and Tertiary Silicenium Ions from Kinetics and Equilibria of Hydride-Transfer Reactions in the Gas Phase. A Quantitative Comparison of the Stabilities of Silicenium and Carbonium Ions in the Gas Phase

Fourier transform ion cyclotron resonance spectroscopy has been used to examine kinetics and equilibria of hydride-transfer reactions of methyl-substituted silanes with various hydrocarbons having well-established gas-phase hydride affinities.The derived hydride affinities, D(R3Si(1+)-H(1-)), for the silicenium ions SiMeH2(1+), SiMe2H(1+), and SiMe3(1+) are 245.9, 230.1, and 220.5 kcal/mol, respectively, to be compared with the values of 270.5, 251.5, and 233.6 kcal/mol for the corresponding carbonium ions.This indicates that the silicenium ions are significantly more stable than the corresponding carbonium ions in the gas phase with H(1-) as a reference base.