A theoretical study on protonation of some halogen substituted pyridine derivatives

The geometries of 12 multi-halogenated pyridine derivatives were optimized using theoretical methods. The Hartree–Fock (HF) method with the 6-31G(d) and B3LYP method with 6-31G(d) basis sets were found to be adequate in calculation of absolute acidity constants, pKa values. A perfect correlation between the computed and experimentally obtained acidity constants, pKa values, was observed.