29788-03-2Relevant academic research and scientific papers
Substituent effects of mono-, bis-, and tris(trimethylsilyl)methyl groups; determination of σ- and σ+-constants
Cook,Eaborn,Walton
, p. 293 - 299 (1970)
The apparent dissociation constants of the acids p-[(Me3Si)xCH(3-x)]C6H4CO2H in 50% aqueous ethanol at 25° have been measured and used to give the following σ-constants for the p-[(Me3Si)xCH(3-x)] groups: x = 1, -0.29; x = 2, -0.33; x = 3, -0.27. The rates of solvolysis of the tertiary chlorides p-[(Me3Si)xCH(3-x)]C6H4CMe2Cl in aqueous acetone have also been measured and used to give the following σ+-constants: x = 1, -0.54; x = 2, -0.62; x = 3, -0.52. The results are consistent with the existence of substantial hyperconjugative electron release from the Me3SiC bonds.
