STRUCTURE OF 3-PHENYL-2-THIOPYRUVIC ACID AS STUDIED BY FT-IR, FT-RAMAN, AND NMR SPECTROSCOPIES

FT-IR, FT-Raman and High Resolution NMR spectra of 3-phenyl-2-thiopyru vic acid (PTPA) have been measured in solution and in the solid state. Spectral assignments were carried out by referring to data of PTPA de rivatives including para-substituted PTPA's, PTPA-d5 and PTPA disulfid e. All of the spectral evidences coherently point out that PTPA exists exclusively as the ene-thiol form both in solution and in the solid s tate. Detailed spectral features of PTPA were discussed in comparison with those of phenylpyruvic acid.