Diphosphine dioxides as extraction reagents for the extraction of the actinides. The anomalous aryl strengthening effect

Journal Article · Thu Jan 01 00:00:00 EST 1987 · Sov. Radiochem. (Engl. Transl.); (United States)

OSTI ID:6950414

Rozen, A M; Nikolotova, Z I; Kartasheva, N A

A cycle of investigations of the extraction of mineral acids, actinides, and lanthanides by diphosphine dioxides of various structures in generalized. It was found that in the extraction of acids (HNO/sub 3/, HClO/sub 4/) monodentately coordinated to the dioxides, the laws previously established, relating the extraction capacity to the structure of the compounds, are fulfilled. In the extraction of the actinides and lanthanides(III, IV, VI), accompanied by bidentate coordination, an effect of anomalous aryl strengthening of the complexes is detected: when electronegative aryl groups are introduced into the methylenediphosphine molecule, the basicity of the dioxide is decreased, while the strength of the complexes, contrary to the established principles, increases substantially. It was found that as a result of the anomaly, the extraction of the actinides(III, IV, VI) is increased by a factor of 150 on two aryl groups and by a factor of 2 x 10/sup 4/ on four aryl groups. The anomalous effect arises when a six-membered ring is closed, is maintained when the anion is replaced (by Cl/sup -/ or ClO/sub 4//sup 2 -/), and is especially great in perchloric acid medium but disappears when the bridge is lengthened, the distance of the aryl groups from the phosphorus is increased by a CH/sub 2/ group, and when the aryls are replaced by groups with the same electronegativity but a different nature, for example, Cl(CH/sub 2/)/sub 2/. The cause of the effect is the transmission of electron density from the phenyl groups into the basic ring of the complex, an increase in the principle solvate number, and possibly aromatization of the ring.

• OSTI ID: 6950414
• Journal Information: Sov. Radiochem. (Engl. Transl.); (United States), Vol. 28:3; Other Information: Translated from Radiokhimiya; 28: No. 3, 407-423(May-June, 1986)
• Country of Publication: United States
• Language: Russian

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ACTINIDES
SOLVENT EXTRACTION
PHOSPHINIC ACIDS
MOLECULAR STRUCTURE
SOLVENT PROPERTIES
RARE EARTHS
ARYL RADICALS
BINDING ENERGY
CHEMICAL BONDS
COMPARATIVE EVALUATIONS
COMPLEXES
COMPLEXOMETRY
ELECTRONEGATIVITY
ELECTRONS
MATERIALS TESTING
NITRIC ACID
ORGANIC SOLVENTS
PH VALUE
STRUCTURAL CHEMICAL ANALYSIS
VALENCE
ELEMENTARY PARTICLES
ELEMENTS
ENERGY
EXTRACTION
FERMIONS
HYDROGEN COMPOUNDS
INORGANIC ACIDS
LEPTONS
METALS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
RADICALS
SEPARATION PROCESSES
SOLVENTS
TESTING
400201* - Chemical & Physicochemical Properties