Posts Tagged ‘overall free energy’

The mechanism of silylether deprotection using a tetra-alkyl ammonium fluoride.

Wednesday, May 25th, 2016
No Gravatar

The substitution of a nucleofuge (a good leaving group) by a nucleophile at a carbon centre occurs with inversion of configuration at the carbon, the mechanism being known by the term SN2 (a story I have also told in this post). Such displacement at silicon famously proceeds by a quite different mechanism, which I here quantify with some calculations.

(more…)

The SN1 Reaction- revisited

Wednesday, November 11th, 2009
No Gravatar

In an earlier post I wrote about the iconic SN1 solvolysis reaction, and presented a model for the transition state involving 13 water molecules. Here, I follow this up with an improved molecule containing 16 water molecules, and how the barrier for this model compares with experiment. This latter is nicely summarized in the following article: Solvolysis of t-butyl chloride in water-rich methanol + water mixtures, which (for pure water) cites the following activation parameters
(more…)