Ab initio study of molecular geometry and the torsional potential in perfluoro (ethyl methyl ether)

Abstract

Molecular geometries, energies, and vibrational frequencies for equilibrium and transition-state conformations of perfluoro(ethyl methyl ether) have been calculated using ab initio molecular orbital theory. Geometries were optimized at the 6-31G(d) level, and single-point energies were also obtained with the 6-31G(d) basis set. MP2 correlation energies were calculated with both bases. Examination of the potential energy surface reveals that a distorted twist-trans structure is the lowest energy conformation. The gauche conformer has an unexpectedly narrow and high-energy minimum, separated from the twist-trans structure by a low torsional barrier