METHYLAMINES BASICITY CALCULATIONS - IN VACUO AND IN SOLUTION COMPARATIVE-ANALYSIS

A purely electrostatic method that does not explicitly take account of specific interactions such as hydrogen bonds has been used to calculate the basicity ordering of methylamines in aqueous solution. The influence of in vacuo energies and solvation energies is discussed by means of quantum calculations and the polarizable continuum model of the solvent. Our results, which reproduce experimental ordering and magnitude quite well, seem to indicate that electron correlation is very important in order to have a good estimation of the inductive effect produced by methyl substitution and that the continuum model is quite suitable for dealing with the solvation of methylamines. Finally a simple electrostatic explanation can be employed to rationalize the behavior of some homologous series in solution.