VIBRATIONAL STUDY OF THIODIGLYCOLIC ACID AND POTASSIUM THIODIGLYCOLATE SALTS

The Raman and infrared spectra of thiodiglycolic acid and its potassiu m salts in aqueous solution were recorded from 4000 to 200 cm(-1). Vib rational assignments were made for all the observed wavenumbers on the basis of isotopic wavenumber shift, depolarization ratios and group w avenumber considerations and comparison with accepted assignments for certain vibrational modes in other similar compounds. The three compou nds (the acid, the acid salt and the neutral salt) belong to the C-s s ymmetry group, but their conformations are different. In the crystalli ne state, the acid salt has a strong hydrogen bond and appears to be o f the A type according to Speakmann's classification.