Neptunium chloride oxides

A radiochemist isolates 8.6 /ng of a chloride of neptunium (atomic weight = 237 g/mole), which she proves has the formula NpCl3. in trying to find the possible valence states of Np, she finds that titration of the 8.6 /xg sample requires 37.5. 1 of 0.00200 N KMn04 solution. To what electrical charge must the Np have been oxidized ... 

The donor action of [NOs]" as an anionic ligand towards thorium(iv) and uranium(iv) in the presence of trimethylphosphine and tris(dimethylamino)phosphine oxide in aqueous media has been found to be very similar. The larger nitrate ion was observed to form more stable species with thorium than the chloride ion whereas in the uranium(iv) case both complexes formed equally readily. A study of the sulphate complexes of uranium(iv), neptunium(vi) and plutonium(vi) in HCIO4-H2SO4 solution showed the stability constants to follow the order U[Pg.453]

Duyckaerts, Landresse and Lysy reported investigations of the solubility of various uranium and neptunium oxides in the molten KCl-LiCl eutectic at 660 °C [231, 252], The solubility product of Np02 in the chloride melt was estimated to be pPNp02 = 20.3 0.5 [252]. 

AnBr3 compounds can be prepared by reaction of HBr with the proper actinide hydride, hydroxide, oxalate hex-ahydrate, or oxide. Structures similar to the trichlorides are observed with the structural change from nine coordination to eight coordination occurring with 6-neptunium tribromide. The triiodides to a-americium triiodide have the same eight-coordinate structure found for the heavier bromides and chlorides. From 6-americium triiodide on, the metals are six coordinate. Thl3 is best formulated as Th(IV), 31, and le. ... 

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