Synthesis of organic ligands for f-element separations. Final report.

摘要

The efficacy of CMP and CMPO (carbamoylmethylphosphonates, carbamoylmethylphosphine oxides) as extractants has stimulated interest in design of new extractants, in particular, bifunctional and trifunctional ligands containing both P(double bond)O and N-O donors. 2,6-bis(diphenylphosphino)pyridine N,P,P-trioxide was selected as a target, with the bifunctional and trifunctional diphenylmethylphosphino analogs as alternate target ligands. The ligands were synthesized and characterized. Their coordination chemistry was studied using Pr, Tb, Yb, Th; a wider range of metal/ligand stoichiometries was found than typically found for other ligands, and the ligands are sufficiently basic that, under some conditions, they displace nitrate ion from the inner coordination sphere, which is unusual for neutral donor ligands. For both 2:1 and 4:1 complexes, the ligand is bonded to the Ln(III) ions in a bidentate manner, and in a tridentate manner for 1:1 and 2:1 complexes. These ligands may be unusually effective solvent extraction agents, and liquid-liquid extraction studies are in progress. (DLC)