Intermolecular Potential Energy Surfaces of CH3OCH3/H2O and CH3OCF3/H2O

Abstract

Theoretical studies of van der Waals complexes provide valuable information about the nature of weak intermolecular forces. Last year, we reported the ab-initio study of the potential energy surfaces of C2H6/H2O and C2H5F/H2O Van der Waals dimmers. In C2H6/H2O, one stable structure was found, and, in C2H5F/H2O, two stable structures were found. In the present study, we have investigated the potential energy surface of C2H5F/H2O in more detail. The computed potential energy surface exhibits four stable structures. Two of them (referred to as ST1 and ST2, respectively) are those in which the H2O molecule exists in the C-C-F plane of C2H5F. The others (referred to as ST3 and ST4, respectively) are those in which the molecular plane of H2O molecule is perpendicular to the C-C-F plane of C2H5F. Both ST1 and ST3 have the H2O molecule in an equatorial location of the C-C axis, and both ST2 and ST4 have the H2O molecule in an axial region of the C-C axis. The details of the potential energy surfaces are discussed.