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Formation of the metal is observed under irradiation of methanol-containing aqueous solutions of cadmium salts with accelerated electrons. The process of precipitation of the metal and its properties was examined. The radiation-chemical yield is (1.7 ± 0.2) × 10-2 g kGy. The efficiency of the radiation-induced reduction of a number of other metals in aqueous media: copper, lead, and thallium, was substantiated. The method may be promising for obtaining deposits of pure and amorphous metals from aqueous solutions of their salts and for purification of aqueous effluents containing these toxic metals. [ABSTRACT FROM AUTHOR]

The reaction of the ozone-oxygen mixture with aqueous suspensions of Np(IV) and Pu(IV) oxalates was studied. Both metal cations and oxalate anions are oxidized in the process. The final products are Np(VI) and Pu(VI) hydroxides. The composition of Np(VI) hydroxide was confirmed by X-ray diffraction analysis. Oxidation of Np(IV) oxalate with oxygen leads to the accumulation of Np(V) oxalate and oxalic acid in the solution. At incomplete oxidation of Np(IV) oxalate with ozone in water, Np(V) is also accumulated. Heating considerably accelerates the ozonation. The possible reaction mechanism is briefly discussed. The Np(V) and Np(VI) ions participate in the catalytic cycle of the decomposition of oxalate ions with ozone. [ABSTRACT FROM AUTHOR]

Precipitation of salts M[NpO(OH)]· nHO (M = Na, K, Rb, Cs) from concentrated alkali solutions at low temperatures (about −10°C) was studied. From solutions with [OH] > 9.5 M, these compounds are isolated as coarse black crystals in high yield without impurity of other phases. The K, Rb, and Cs salts crystallize in the form of the previously studied compounds K[NpO(OH)]·2HO and M[NpO(OH)]·3HO (M = Rb, Cs). In the case of Na, a new hydrate Na[NpO(OH)]·6HO was obtained, and its crystal structure was determined. Crystals of the hexahydrate consist of centrosymmetrical tetragonal-bipyramidal anions [NpO(OH)], crystallographically independent Na(1) and Na(2) cations, and water molecules. The coordination surrounding of the Np atom is characterized by noticeable difference (Δ = 0.0203 Å) in the Np-O bond lengths in the equatorial plane of the bipyramid. The [NpO(OH)] anions are combined with the Na(2) cations to form infinite chains [Na(2)NpO(OH)(HO)] in such a manner that the lateral edges of the anion are simultaneously the lateral edges of the Na(2) coordination polyhedron. Incorporation of one of the two crystallographically independent O atoms of the NpO group into the Na(2) coordination surrounding is responsible for a noticeable difference in the Np-O bond lengths in the equator of the [NpO(OH)] anion. The types of hydrogen bonding in the structures of Na3[NpO(OH)]· nHO ( n = 0, 2, 4, 6) are compared. [ABSTRACT FROM AUTHOR]

New crystalline compounds of the general composition Co(NH3)6[PuO2L]2A · nH2O, where L = CH2(COO)2 and A = HCOO, CH3COO, C2H5COO, and HL, were prepared by adding a small excess of Co(NH3) ions to freshly prepared neutral Pu(V) malonate solutions containing single-charged organic anions. The complexes are sparingly soluble in water and fairly stable when stored in air; they have a similar structure. Previously unknown double Np(V) malonates Co(NH3)6[NpO2L]2A · nH2O, where A = HCOO, CH3COO, and C2H5COO, isostructural with the corresponding Pu(V) compounds, were also prepared. The IR spectra of the new compounds were measured, and their behavior at heating was examined. [ABSTRACT FROM AUTHOR]

Double monooxalates MPuO2C2O4 · nH2O with NH and Cs+ ions in the outer sphere were isolated from weakly acidic aqueous solutions of Pu(V). The unit cell parameters of these compounds were determined. The ammonium salt is isostructural to its neptunyl(V) analog; its structure is characterized by the monodentate cation-cation interaction of plutonyl(V) ions. Cesium plutonyl(V) salt isolated from a solution is not isostructural to the neptunyl(V) compound and is easily dehydrated at room temperature to form tetrahydrate, which transforms to dihydrate at 110°C. The latter compound, according to the IR spectra, can have a network system of cation-cation bonds involving PuO. [ABSTRACT FROM AUTHOR]

Double U(VI) phthalates with NH, K+, and Cs+ ions in the outer sphere were synthesized. The X-ray phase analysis shows that their structures are similar. Single crystals were prepared and the structure of K4[(UO2)4(μ3-O)2(C6H4C2O4)4] ⋅ 3H2O was solved. In the [(UO2)4O2(C6H4C2O4)4]4− anions forming the main structural motif, each bridging oxygen atom μ3-O combines one pentagonal and two hexagonal bipyramids, which, in turn, are combined in centrosymmetrical tetramers. The phthalate ions have coordination capacity equal to 3; each ligand coordinates U(1) in the bidentate fashion via one carboxy group and U(2) in the bidentate fashion to form a planar seven-membered chelate ring. [ABSTRACT FROM AUTHOR]

New crystalline compounds of the composition Co(NH3)6[PuO2L]2A ⋅ nH2O, where L = C3H2O4 and A = NO3, ClO4, Cl, and Br, were obtained by addition of a small excess of Co(NH3) ions to freshly prepared neutral malonate solutions of Pu(V). They are fairly stable in storage in air and isostructural to the corresponding Np(V) compounds. Thermal behavior of the compounds synthesized was studied, and their IR spectra were measured. [ABSTRACT FROM AUTHOR]

Crystalline compounds of the general composition Co(NH3)6PuO2(C2O4)2· nH2O ( n = 2, 3, 5) were isolated from freshly prepared neutral oxalate solutions of Pu(V) by addition of Co(NH3)6 ions. These compounds are fairly stable in storage in air and poorly soluble in water. Previously unknown double Np(V) oxalates Co(NH3+ ions. These compounds are fairly stable in storage in air and poorly soluble in water. Previously unknown double Np(V) oxalates Co(NH3)6NpO2(C2O4O ( n = 2, 5) were also synthesized and studied. All the compounds of Pu(V) and Np(V) of the same composition are mutually isostructural. The behavior of these compounds at heating was studied, and their IR spectra were measured. The optical spectra of new Np(V) compounds were measured. [ABSTRACT FROM AUTHOR]2O ( n = 2, 5) were also synthesized and studied. All the compounds of Pu(V) and Np(V) of the same composition are mutually isostructural. The behavior of these compounds at heating was studied, and their IR spectra were measured. The optical spectra of new Np(V) compounds were measured. [ABSTRACT FROM AUTHOR]

NaPuO2C2O4·3H2O was isolated from a freshly prepared oxalate solution of Pu(VI) by reduction with a stoichiometric amount of hydrazine hydrate. Heating of the compound results in its stepwise dehydration with successive formation of the monohydrate and anhydrous salt. According to powder X-ray patterns, NaPuO2C2O4· nH2O ( n = 3, 4) is isostructural to the corresponding analogs NaNpO2C2O4· nH2O. The unit cell parameters of NaNpO2C2O4·H2O and NaPuO2C2O4· nH2O ( n = 3, 1) were determined. The results of the X-ray analysis and the electronic and IR spectra of the neptunyl(V) and plutonyl(V) crystalline compounds suggest the presence of cation-cation bonds in NaPuO2C2O4· nH2O ( n = 1, 0). [ABSTRACT FROM AUTHOR]