| Popis: |
Ab initio calculations on pyruvic acid have been carried out at the HF/4–31G, 6–31G∗∗ and MP2 4–31G levels. The geometries of the Tc, Tt, Ct and Cc conformations were fully optimized at these levels. At all levels of calculation, Tc was found to be the lowest-energy species, in accordance with experimental data. The potential-energy surface was determined at various levels of approximation in order to study the basis-set dependence of the energetics of this rather important molecule. The geometries of the conformers and their vibrational spectra are given and compared with existing experimental data. In addition, the unimolecular decarboxylation reaction of pyruvic acid, leading to an unstable carbone, was also studied. |
