Molecular mechanics (MM3) parameterization for oxocarbenium ions

The physical properties of a diverse group of 12 oxocarbenium ions have bee n studied with ab initio calculations at the MP2/6-31+G* level of theory. B ased on theoretically derived properties such as molecular equilibrium geom etry, dipole moment, and vibrational frequencies, a molecular mechanics (MM 3) force field has been developed with the assistance of the programs TORSM ART and MPMSR, components of our artificial parameter development and refin ement method. The MM3 force field is now able to reproduce bond lengths, bo nd angles, moments of inertia, dipole moments, torsional energy profiles, a nd vibrational frequencies of oxocarbenium ions, which will allow further s tudies of glycoside hydrolysis and their rates of reaction. (C) 2000 John W iley & Sons, Inc.