Computational Methods in Organic Chemistry. 3. Correction of Computed Enthalpies for Multiple Conformations

The first explicitly calculated G3(MP2) enthalpies and Gibbs energies of formation for undecane through eicosane are presented. These values, when corrected for the presence of multiple conformations, are found to be within 4 and often 2 kJ/mol of the experimental values. The derivation of the corrections for the enthalpies, which differ from those of the Gibbs energies published earlier, is presented and also applied to the first 10 homologues of the alkene, alkyne, alcohol, and thiol families.