CRYSTAL-STRUCTURES OF SODIUM DIMETHYL SULFOSUCCINATE AND SODIUM DIETHYL SULFOSUCCINATE

The crystal structures of sodium dimethyl sulfosuccinate and sodium di ethyl sulfosuccinate have been determined by the single crystal X-ray diffraction method. Sodium dimethyl sulfosuccinate (SDMS, C6H9O7SNa.H2 O, Mr = 266.20) crystallizes in a triclinic space group P (1) over bar with unit cell dimensions a = 5.5971 (8), b = 6.5388 (5), c = 15.267 (2) Angstrom, alpha = 77.855 (8), beta = 85.90 (1), gamma = 84.95 (1)d egrees. The crystal of sodium diethyl sulfosuccinate (SDES, C8H13O7SNa .3H(2)O, Mr = 330.29) has a monoclinic space group C2/c with unit cell dimensions a = 34.754 (3), b = 6.0322 (7), c = 15.0777 (9) Angstrom, beta = 104.385 (7)degrees. In the SDMS and SDES crystals, the Na+ ion, which is coordinated to six oxygen atoms, forms an octahedral structu re. For SDMS, the Na+ ion is coordinated to four oxygen atoms of SO;gr oups and to the two oxygen atoms of water molecules of hydration. For SDES, the Na+ ion is coordinated to the oxygen atom of the beta-chain C=O group, one of the SO3- oxygen atoms and four oxygen atoms of hydra ting water molecules. It was found that splitting of the C=O stretch b and caused by the Na...O=C coordination occurs in the IR and Raman spe ctra of SDES. (C) 1998 Elsevier Science B.V. All rights reserved.