ABINITIO MOLECULAR-ORBITAL STUDY OF THE STRUCTURES AND STABILITIES OF THE C2H4O+.ISOMERS

A detailed study of 11 possible C2H4O+• isomers has been carried out with the aid of ab initio molecular orbital theory. Calculations have been performed with minimal (STO-3G), split-valence (4-31G), and split-valence + polarization (6-31G*) basis sets and with restricted (RHF) and unrestricted (UHF) Hartree-Fock procedures. Geometries have been fully optimized and relative energies calculated. Three well-established C2H4O+• isomers (CH2=CHOH+•, CH3CHO+• and CH2OCH2+•) and a fourth more recently postulated isomer (CH2OCH2+•) are all found to be stable structures and to have relatively low energies. Five additional isomers (CH2CH2O+, CH3C=OH+• CH3O=CH+• CH=CHOH2+• and CH2= COH2+•) have been identified as having reasonable prospects for experimental observation. The reaction paths for the possible interconversion of the closed ethylene oxide ion to the two ring-opened isomers have been examined. © 1979, American Chemical Society. All rights reserved.