Synthesis of N,N′-dimethyl-N,N′-didecyl-3-oxa-diglycolamide for extraction of lanthanides

A novel extractant, N,N'-dimethyl-N,N'-didecyl-3-oxa-diglycolamide (DMDDDGA), was designed and synthesized for extraction of lanthanides in the nuclear fuel reprocessing. The extraction behaviors of Gd, Dy, Er and Ho from nitric acid solution were investigated using DMDDDGA in chloroform. The effects of nitric acid concentration, extractant concentration, and temperature on the extraction were investigated. The distribution ratio of lanthanides increases with concentrations of the extractant and nitric acid, but decreases with increasing temperature, which indicates that the extraction process is exothermic. FT-IR spectra indicated that the C=O in DMDDDGA is coordinated with metal ion in the extracted species and the stoichiometries of lanthanides(III) complex are Gd(NO3)(3)center dot 3DMDDDGA, Dy(NO3)(3)center dot 4DMDDDGA, Er(NO3)(3)center dot 4DMDDDGA, and Ho(NO3)(3)center dot 4DMDDDGA.