Abstract A homologous series of sodium dialkylsulfosuccinates, which are straight-chain analogues of Aerosol-OT with various chain lengths (dimethyl, diethyl, dibutyl, dihexyl, diheptyl, dioctyl, didecyl, diundecyl and didodecyl), has been synthesized. In order to assign the IR bands of the CH2 scissoring and CH deformation modes of the succinate segment, sodium dideuteratedmethylsulfosuccinate and sodium dideuteratedethylsulfosuccinate have also been synthesized. IR absorption spectra have been recorded for these mono-, di- and multihydrate samples in the solid state. In particular, IR bands in the 12501500cm1 region have been compared for sodium dimethylsulfosuccinate, sodium diethylsulfosuccinate and sodium diheptylsulfosuccinate, whose crystal structures are known. The CH2 scissoring and CH deformation modes of the succinate CH2-CH portion strongly depend upon the environment of hydration and on the length of the hydrocarbon portions.