Relationships between the structure of monohexadecyl hydrocarbylphosphonates and their behaviour in extraction of Yb(III) and Lu(III)

The structure-behaviour relationships of a class of highly hindered monohex adecyl hydrocarbylphosphonates, R-1 ((RO)-O-2)P(O)OH, where R-1 represents CH3, C2H5, i-C3H7, cyclo-C6H11 or C6H5, and R-2 represents C4H9(C2H5) CHC2H 4 (C6H13)CH or C6H13(CH3)CHCH2 (C6H13)CH, in the extraction of Yb(III) and Lu(III) from chloride medium are investigated. The results show that the ex traction and separation abilities for Yb and Lu decrease with increasing th e steric hindrance of the substituents in extractant molecules.