| Abstract: | Bifunctional sulfides and sulfoxides containing carboxy, carbamoyl, or acylamino groups in the  -position are synthesized, and their IR spectra were studied. An unusual decrease in the frequencies of the carbonyl vibrations (by 20–34 cm–1) was found for thiodipropionic acid, its amides, and bis(-acylaminoethyl) sulfides by comparison with the corresponding sulfoxides. The low-frequency shift of the CO band in these carbonylsulfides was not, as expected, associated with the intramolecular S...O coordination, since the x-ray structural investigation of thiodipropionic acid and bis(2-trifluoroacetylaminoethyl) sulfide did not show short intra- and intermolecular contacts involving the sulfur atom. Both structures contain intermolecular hydrogen bonds (C=O...HO or C=O...HN).For previous communication, see 1].A. N. Nesmeyanov Institute of Heteroorganic Compounds, Russian Academy of Sciences, 117813 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 8, pp. 1766–1775, August, 1992. |
