Study on Species of Heavy Lanthanides(III) Chelates Extracted into Organic Phase with 5,7-Dichloro-8-hydroxyquinoline

The nature of species formed in the extraction of lanthanides Ln(III) (where Ln = Tb, Dy, Ho, Er, Tm and Yb) with 5,7-dichloro-8-hydro xyquinoline (HL) in CHCl$\text{}_{3}$ from water or water-methanol phase was examined. It was stated that during the extraction from water phase the chelates LnL$\text{}_{3}$ (Tb, Tm), seven-coordinated self-adducts LnL$\text{}_{3}$ ÷ HL (Er, Ho) or both types of these species (Dy, Yb) were extracted. In the presence of methanol (MeOH) in the aqueous phase the eight-coordinated mixed species of the type LnL$\text{}_{3}$·2MeOH were observed.