No abstract

The distribution of calcium, strontium, barium and scandium between aqueous and organic phases was studied using 0.1 M HNO3 or 0.01 to 0.1 M HCl as the aqueous phase and solutions of selected derivatives of organophosphoric reagents containing the conventional =P(O)NHP(O)= bifunctional group or the analogous trifunctional or tetrafunctional group in various organic solvents as the organic phase. The effect of substitution of one ester group by an OH or NH2 group was examined. While for the alkaline earth metals the distribution ratio increases if the bifunctional group is replaced by a higher-functional group, the reverse is true for scandium. The extraction efficiency is improved by the presence of OH or NH2 substituent groups. The composition of the extracted species was inferred by logarithmic analysis and the corresponding extraction constants were calculated.

The distribution of scandium and hafnium between 0.1 or 1.0 mol l-1 HNO3 and solutions of monoalkyl methanephosphonates (HA; alkyl = methyl, propyl, butyl, isobutyl, pentyl, 2-methylbutyl, cyclohexyl, 1,2,2-trimethylpropyl) in chloroform and 1,1,2,2-tetrachloroethane has been studied. The organic solvents mentioned allow to obtain the optimum values of partition coefficients of the two metals. The corresponding extraction constants of the ScA3(HA)x and Hf(NO3)4(HA)4 complexes have been calculated.

The distribution of Ag, Zn, Cd, Sc, Eu, Hg, and Hf between mineral acids (HNO3, HCl) and benzene solutions of selected sulfur derivatives of organophosphoric reagents containing the P(X)NHP(X) or (RO3)PS group (X = O, S) was examined. The effect of the organic solvent was also investigated for Hg and some of the reagents. The composition of the complexes extracted was identified, and the corresponding extraction constants were calculated.

The distribution of chelate-forming reagents on a basis of arylimidodiphosphate between different organic solvents and 0.1 mol L -1 HNO 3 has been studied by liquid-liquid extraction of 46 Sc. The values of dimerization constants K 2 in selected solvents, particularly on the chlorine and chlorine-fluorine hydrocarbon basis as well as distribution constants K D (HA) have been determined.