PK(A) VALUES OF AMINES IN WATER FROM QUANTUM-MECHANICAL CALCULATIONS USING A POLARIZED DIELECTRIC CONTINUUM REPRESENTATION OF THE SOLVENT

Solvent effects on protonation equilibria of various aliphatic, alicyc lic, and aromatic amines were estimated by means of a self-consistent isodensity-polarized electrostatic continuum model in combination with the B3LYP/6-31G and B3LYP/aug-cc-pVDZ//B3LYP/6-31G* calculation sche mes. Our results suggest that the found relationship between calculate d relative and experimental basicities in water can be used for interp olation or extrapolation in order to calculate pK(a) values of organic bases with variable structural properties. The found standard deviati on of calculated pK(a) values amounts to 0.7 pK(a) units. In this pape r, we note successful use of this strategy as well as its limits.