Analysis of the basicity of substituted dimethylamines in different solvents by theoretical descriptors

By using theoretically determined descriptors in quantitative structure-property relationships, quick and good a priori predictions of molecular properties can be accomplished. In this study, theoretical linear solvation energy relationship descriptors are used to analyze structural effects that contribute to the basicity variation of substituted dimethylamines in different solvents. A multilinear regression (MLR) analysis approach is used to generate equations and, owing to the goodness of the 'fit' of the different MLR equations, the descriptors used account very well for the structural effects that determine the relative basicity of dimethylamines. Good agreement is obtained between the basicity values predicted by this method and the experimental basicity values of 14 substituted dimethylamines in eight solvents and the gas phase. The Lewis basicity epsilon(B) and the polarizability/dipolarity pi(i) are the important factors that contribute to basicity variation. For the basicity of NCCH2N(CH3)(2), a good prediction was not achieved and a discussion is presented. Copyright (C) 2001 John Wiley Sons, Ltd.