SummaryThe conformational equilibrium of ethylene glycol (CH2OHCH2OH) has been examined by performing geometry optimizations at the 6-31G*, MP2/6-31G* and 6-31G** levels. Final energies have been calculated at the MP3 level with the optimized geometries. The two most stable conformers are atGg′ andgGg′ but it is verified that the inclusion of electronic correlations reduces their energy difference of 0.6 kcal/mol at the HF level to less than 0.2 kcal/mol. The possible coexistence of the two most stable conformers is in agreement with some previous studies of Frei et al. For thetXg′ conformer a detailed analysis of the intramolecular potential as a function of rotation around the C-C bond is also reported.

The two most stable conformers of ethylene glycol are atGg′ andgGg′, with electronic correlations reducing their energy difference to less than 0.2 kcal/mol.

Ab initio study of the conformational equilibrium of ethylene glycol

Key Takeaway: The two most stable conformers of ethylene glycol are atGg′ andgGg′, with electronic correlations reducing their energy difference to less than 0.2 kcal/mol.