An ab initio study of three (ethane-1,2 diol/water) complexes

Three (ethane-1,2 diol/water) complexes have been studied using ab initio calculations at the MP2 level. In two complexes, the ethane-l,2 diol structure is close to its gas phase experimental structure (presence of an intramolecular hydrogen bond HE and the O-C-C-O dihedral angle is gauche) while the intramolecular HE is disrupted by the presence of a water molecule in the third (tGg'a). Computations have shown that most of the experimental observations regarding the solvation of ethane-1,2 diol in water may be reproduced only by considering the tGg'a complex (absence of intramolecular HE, O-C-C-O dihedral angle of 72-74 degrees), which is also more stable than the other two by 2 kcal mol(-1). (C) 1998 Published by Elsevier Science B.V. All rights reserved.