Distribution features of scandium and thorium complexes with alizarin derivatives in aqueous-organic systems

Complexation of thorium and scandium with alizarin and products of its cond ensation with formaldehyde and secondary amines was studied in aqueous-acet one solutions. The chemistry and conditions of distribution of these comple xes between aqueous-acetone solutions and 1-butanol and a 1-butanol-chlorof orm mixture were examined. The yield of Sc and Th complexes in aqueous-acet one solutions is maximal at pH 2.5-6.0, which coincides with pH of maximal extraction of the complexes with 1-butanol. The compositions, dissociation constants, and molar extinction coefficients of these complexes were determ ined spectrophotometrically. Scandium and thorium complexes with the R : Me molar ratio equal to 2 : 1 are quantitatively extracted in the organic pha se from acetate buffers containing perchlorate and trichloroacetate ions. T he structure of the extracted complexes was determined by IR and H-1 NMR sp ectroscopy. The experimental results showed that 1,2-dihydroxyanthraquinone is the most effective extractant for thorium and scandium ions.