PREDICTION OF HYDROGEN-BOND BASICITY FROM COMPUTED MOLECULAR ELECTROSTATIC PROPERTIES - IMPLICATIONS FOR COMPARATIVE MOLECULAR-FIELD ANALYSIS

Computed molecular electrostatic properties have been evaluated as pre dictors of hydrogen bond basicity for a set of heterocycles with nitro gen as the hydrogen bond acceptor. The properties were (a) the electro static potential local minimum, V-min, in the region of the nitrogen l one pair, (b) the electrostatic potential, V-beta(r) and (c) the magni tude of the electric field strength, \F-beta(r)\, at points along the lone pair axis, defined by the distance r from nitrogen. V-min was fou nd to be an excellent predictor of hydrogen bond basicity. The ability of the other parameters to fit the data was maximised at r = 1.4 Angs trom for V-beta(r) and at r = 2.5 Angstrom for \F-beta(r)\ which has i mplications for Comparative Molecular Field Analysis.