Structures and Vibrational Frequencies of Pyruvic Acid:Density Functional Theory Study

Density functional theory BLYP(using Beckes and Lee-Yang-Parr’s correlation functionals),ab initio Hartree-Fock(HF)and hybrid DFT/HF B3LYP calculations were carried out to study the structure and vibrational spectra of pyruvic acid.Molecular conformation calculations were made for two possible conformers(eclipsed and staggered with respect to the methyl group)of the compound Calculated results show that:the stable conformer of pyruvic acid is the eclipsed one;The BLYP/6-31G* and scaled HF/6-31G* frequencies correspond well with each other and with available experimental assignment of the normal vibrational modes.On the basis of the comparison between calculated and experimental results,assignments of fundamental vibrational modes are examined.