AB-INITIO SCF INVESTIGATION OF THE INTRAMOLECULAR HYDROGEN-BONDING IN DELTA-AMINOPENTANOIC ACID

The potential energy surface of the neutral form of delta-aminopentanoic acid was investigated by means of ab initio 4-31G SCF calculations. Four symmetry unique local minima are stabilized by an intramolecular O-H...NH2 hydrogen bond. The geometries, energies, and wave numbers of these conformers are reported. The hydrogen bond is discussed with respect to all reactions of these conformers and in comparison with the homologues glycine, beta-alanine, and gamma-aminobutyric acid and also with the bimolecular adducts between formic acid, acetic acid, and propionic acid, on the one hand, and ammonia, methylamine, and ethylamine, on the other hand.