Collect. Czech. Chem. Commun. 1994, 59, 1251-1260

Study of Hydrogen Bonding in Carboxylic Acids by the MNDO/M Method

Michal BureŇ° and Jaroslav Bezus

Department of Physical Chemistry, Prague Institute of Chemical Technology, 166 28 Prague 6, Czech Republic


The semiempirical methods MNDO/M, AM1 and PM3 were applied to the study of hydrogen bonds in carboxylic acids. The calculated hydrogen bond lengths and enthalpies of dimerization were compared with experimental data. The AM1 method fails to properly describe systems with strong hydrogen bonds. The PM3 method predicts the hydrogen bond lengths correctly but underestimates systematically the enthalpies of dimerization. MNDO/M appears to be a promising method for the treatment of association of carboxylic acids.