The crystal structures of sodium dimethyl sulfosuccinate and sodium diethyl sulfosuccinate have been determined by the single crystal X-ray diffraction method. Sodium dimethyl sulfosuccinate (SDMS, C6H9O7SNa· H2O, Mr= 266.20) crystallizes in a triclinic space group P 1 ̄ with unit cell dimensions a= 5.5971 (8), b= 6.5388 (5), c= 15.267 (2) A ̊, α= 77.855 (8), β= 85.90 (1), γ= 84.95 (1)°. The crystal of sodium diethyl sulfosuccinate (SDES, ...