ELECTRONEGATIVITY AND HARDNESS OF DISJOINT AND TRANSFERABLE MOLECULARFRAGMENTS

Approximate Fukui indices have been derived from the atomic volumes of molecules as calculated within the framework of Bader's atoms-in-mole cules theory. Parameters of the bond critical points {del rho(r(c))n = 0} have been explored in calculating the hardness (eta) and electrone gativity (chi) of a selection of typical chemical groups, widely consi dered as transferable entities. Resulting eta and chi indices demonstr ate strong dependence on the nature of neighboring atoms and on the bo nd system vicinal to the group; however, they are not directly related to the group charges.