Hyperconjugation reactions calculations

Solvolytic experiments specifically designed to test Bartell s theory were carried out by Karabatsos et al. (1967), who were primarily interested in an assessment of the relative contributions of hyperconjugation and non-bonded interactions to secondary kinetic isotope effects. Model calculations of the (steric) isotope effect in the reaction 2- 3 were performed, as well as that in the solvolyses of acetyl chloride... 

Although the geometric relationship suggested by Shiner and by Sunko and their co-workers clearly demonstrates that hyperconjugation is the major contributor to the secondary /3-deuterium KIE in carbocation reactions, Williams (1985) has suggested that there is a significant inductive component to these KIEs. Williams used ab initio MO methods to calculate the geometries of the substrates and the isopropyl carbocation formed in a gas-phase heterolysis (30) of series of isopropyl derivatives at the RHF/4-31G level. 

To express the collective solvent reaction coordinate as in equation (6), it is necessary to define the specific diabatic potential surface for the reactant and product state. This, however, is not a simple task, and there is no unique way of defining such diabatic states. What is needed is a method that allows the preservation of the formal charges of the fragments of reactant and product resonance states. At the same time, solvent effects can be incorporated into electronic structure calculations in molecular dynamics and Monte Carlo simulations. Recently, we developed a block-localized wave function (BLW) method for studying resonance stabilization, hyperconjugation effects, and interaction energy decomposition of organic molecules.20-23 The BLW method can be formulated to specify the effective VB states.14... 

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