Menschutkin reactions of bicyclic aliphatic amines and of pyridine derivatives with methyl iodide. Extended Brönsted treatements and isokinetic relationships in acetonitrile–methanol

Abstract

The rate constants, activation parameters for the Menschutkin reactions for five bases with methyl iodide, and the enthalpies of solution for the relevant species of the reactions have been determined in acetonitrile-methanol. The bases are quinuclidine, 1,4-diazabicyclo[2.2.2]octane, and 4-cyano-, 4-t-butyl-, and 4-dimethylamino-pyridine. The coefficients of empirical energy correlations defined in terms of ‘more physical’ energies, extended Brönsted treatments, α_phys, and isokinetic temperatures, β_phys, have been determined for these reactions. Discussion is provided on the physical meaning of these coefficients in relation to the characteristics of the activated complex.