Complexing properties of α-isosaccharinate: thorium

The complexation of Th with α-isosaccharinate has been studied using liquid-liquid-extraction techniques. An organic phase consisting of 0.025 M acetylacetone in toluene was used with a 1.0 M NaClO4 aqueous phase kept at pH 8 in a thermostated AKUFVE unit at 25 C. The concentration of α-isosaccharinate (ISA-) in the aqueous phase was incrementally increased and samples of equal volumes were taken from the two phases and analyzed in a liquid scintillation detector. Stability constants, βpt, for the complexation reaction Th4+ + pISA- ↔ Th(ISA)p(4-p)+, were determined to be log β125C = 12.56 ± 5.01, log β225C 19.38 + 0.35/ - 0.95, and log β325 C = 21.30 ± 0.26. (orig.)