THEORETICAL INVESTIGATIONS ON 1,2-ETHANEDIOL - THE PROBLEM OF INTRAMOLECULAR HYDROGEN-BONDS

The conformational space of 1,2-ethanediol is studied on the basis of ab initio and semiempirical calculations. All possible conformers are treated. The relative energies of the conformers are systematically st udied using various basis sets up to 6-311 + G(3df, 3pd) in order to p erform calculations as accurate as possible within a reasonable amount of computer time. Electron correlation is included using Moller-Pless et perturbation theory. We propose two methods to evaluate the basis s et superposition error associated with the intramolecular hydrogen bon d appearing in some of the conformers. The results of semiempirical ca lculations are compared with these ab initio calculations. (C) 1996 by John Wiley & Sons, Inc.