Effect of substituents at the nitrogen atom in diaryl [dialkyl(diaryl)carbamoylmethyl]phosphine oxides on their extraction ability and solubility
- Vernadskii Institute of Geochemistry and Analytical Chemistry, Moscow (Russian Federation); and others
Extraction of nitric acid and americium(III) with dichloroethane solutions of [diphenyldialkyl(diaryl)carbamoylmethyl]phosphine oxides containing various substituents at the nitrogen atom has been studied. Complexes with one, two, or three acid molecules per reagent molecule are extracted from nitric acid solutions. The extraction constants of nitric acid (K{sub ex}{sup HNO3}) with all reagents have been calculated. The K{sub ex}{sup HNO3} is linearly dependent on the reagent basicity (pK{sub a}). Americium (III) is extracted by octyl-substituted reagents as di- and trisolvates and by other reagents as disolvates. With increasing pK{sub a}, the extraction constants of americium (K{sub ex}{sub Am}) increase, irrespective of the nature of substituent at the nitrogen atom. In extraction of americium (III) with reagents aryl-substituted at the nitrogen atom, no anomalous aryl strengthening (AAS) is observed. The effect of alkyl substituents at phosphorus and nitrogen atoms on the extraction ability of the reagents is almost identical. The difference in this effect is revealed only in the systems with aryl-substituted reagents owing to effect of AAS.
- OSTI ID:
- 175702
- Journal Information:
- Radiochemistry, Journal Name: Radiochemistry Journal Issue: 5 Vol. 37; ISSN RDIOEO; ISSN 1066-3622
- Country of Publication:
- United States
- Language:
- English
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