Actinide complexes ethylenediamine

Table 9 Some Complexes ot Ethylenediamine and other Diamines with Actinide(IV) Compounds ...

The ZEALEX Process Researchers from KRI have shown that the zirconium salt of dibutyl phosphoric acid (ZS-HDBP) was soluble in Isopar-L in the presence of 30% TBP. This super PUREX solvent, known as ZEALEX, extracts actinides (Np-Am) together with lanthanides and other fission products, such as Ba, Cs, Fe, Mo, and Sr from nitric acid solutions. The extraction yields depend on both the molar ratio between Zr and HDBP in the 30% TBP/Isopar-L mixture and the concentration of HN03 (232). Trivalent transplutonium and lanthanide elements can be stripped together from the loaded ZEALEX solvent by a complexing solution, mixing ammonium carbonate, (NH4)2C03, and ethylenediamine-N.N.N. N -tetraacetic acid (EDTA). An optimized version of the process should allow the separation of... 

Hexamminecobalt(III) salt cannot be used as a precipitant in the oxalato complex precipitation system because it precipitates as hexamminecobalt(III) oxalate. Besides the hexaureachro-mium(III) salt, hexamminechromium(III), tris(ethylenediamine)cobalt (III) or tris(trimethylenediamine)cobalt(III) salts can be used as precipitants. Hexamminechromium(III) and tris(ethylenediamine) cobalt (III) salts form precipitates with actinide(IV) or (VI) oxalato complex ions, whereas tris(trimethylenediamine)co-balt(III) salt forms precipitates with Th(IV) or U(VI) oxalato complex ions leaving Pu(IV) ion in the supernatant solution.Therefore, this reagent plays the role of both a separating agent and a precipitant and is applicable for the separation of Pu(IV) ion from Th(IV) or U(VI) ion. 

Studies of Ln(in) nitrilotriacetate (539) and ethylenediamine (540) complexes have been reported. In the latter case a contact mechanism is responsible for the shifts in the lighter lanthanides (up to Ho) whereas a pseudocontact shift is dominant for the remainder of the series. Some novel lanthanide-cobalt sandwich complexes have also been reported. (587) Uranium(iv) complexes continue to be the most extensively studied of the actinide ion complexes. Appreciable dipolar interactions are expected to arise from the orbitally degenerate ground term arising from the 5f configuration of U(iv). However, in practice isotropic shifts of U(iv) complexes are not dominated by dipolar interactions. 

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