Actinide acetates, amine extraction

Anion Exchange and Amine Extraction of Hexavalent Actinide Acetates... 

Spectrophotometric studies were used to identify the anionic hexavalent actinide acetate complexes present in aqueous and nonaqueous solutions, anion exchange resins, and amine extracts. The previously unreported tetraacetate complexes, M02(CJd 0i),, were identified in all these systems. The formation constant for the reaction +... 

The triacetate uranyl complex (24) is structurally similar to the trinitrate uranyl complex (6) (three bidentate ligands arranged equa-torially around the uranyl O—U—O axis). It was expected that the visible, near ultraviolet spectrum of the triacetate uranyl complex would be similar to the spectrum of U02(N03)3 as are the spectra of 1102(804)3, 1102(003)3 , and other uranyl complexes which apparently have the same structure (17). The absorption spectrum of uranyl acetate extracted into tri-n-octylamine in xylene from dilute acetic acid is different from the trinitrato uranyl spectrum. This indicates that the triacetate uranyl complex is probably not the species involved. By analogy to the uranyl nitrate system 14), formation of a tetraacetate uranyl complex might be expected. The purpose of this work is to determine the nature of the anionic hexavalent actinide acetate complexes and to identify the species involved in the amine extraction and anion exchange of the hexavalent actinides from acetate systems. 

The actinide (VI) acetate system discussed here and the actinide (VI) sulfate system to be discussed later (17) represent the only cases known to us in which observable mixtures of labile anionic complexes of a given metal are extracted from an acid solution by susbtituted amines. The present system represents the only one in which the diluent is the only major factor controlling the ratio of species in the organic phase. The principle mechanism by which the nature of the diluent appears to determine the ratio of species in the organic phase in this system is by... 

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