Thus, the formation of the monosubstituted product prevails when using a Grignard reagent at 0[degrees]C.
In the case of the Grignard reagent, the monosubstituted product is achievable at 0 [degrees]C because the activation energy for the second substitution is higher than that of the first.
Chemical Bonding and the Equilibrium Composition of Grignard Reagents in Ethereal Solutions.
After the reaction mixture had cooled down the concentration of the Grignard reagent was determined.
The reaction vessel equipped with a magnetic stirrer and containing 40 mL of the Grignard reagent was thermostatted.
05 mL of silane was added to 15 mL of the Grignard reagent (providing a 20-40-fold excess of the Grignard reagent), and the temperature change of the reaction solution (less than 1[degrees]C) was recorded as a plot of temperature vs.
The first three entries in Table 2 represent a variation of the donor solvent in the Grignard reagent.
Replacement of the n-butyl group by isopropyl in the Grignard reagent increases the equilibrium constant by a factor of two in accordance of increasing hindrance to coordination with the donor.
Replacement of an ethoxy group by isopropyl in the silane, and particularly the substitution of alkyl groups in the Grignard reagent, leads to a decrease in rate constants by more than two powers of ten.
Pseudo-first-order rate constants in toluene at 20[degrees]C Silane Grignard reagent Titrated conc.