Uranyl salt

Actinide Peroxides. Many peroxo compounds of thorium, protactinium, uranium, neptunium, plutonium, and americium are known (82,89). The crystal stmctures of a number of these have been deterrnined. Perhaps the best known are uranium peroxide dihydrate [1344-60-1/, UO 2H20, and, the uranium peroxide tetrahydrate [15737-4-5] UO 4H2O, which are formed when hydrogen peroxide is added to an acid solution of a uranyl salt. 

In 1896, Becquerel discovered that uranium was radioactive (3). Becquerel was studying the duorescence behavior of potassium uranyl sulfate, and observed that a photographic plate had been darkened by exposure to the uranyl salt. Further investigation showed that all uranium minerals and metallic uranium behaved in this same manner, suggesting that this new radioactivity was a property of uranium itself In 1934, Fermi bombarded uranium with neutrons to produce new radioactive elements (4). 

Several proteins were reported to function as enzymes for the dissimilatory reduction of metals and nonessential elements. As Usted in Table 16.4, the most frequently reported proteins involved in metal reduction are the cytochromes from sulfate-reducing bacteria. The focus on these cytochromes supports the initial papers by Lovley and colleagues in which they reported that reduced cytochrome Cs from Desulfovibrio vulgaris Hildenborough reduces uranyl salts (Lovley et al. 1993a) and chromate (Lovley and PhUhps 1994). 

During the last ten years, studies of luminescence and photochemistry of polypyridyl Ru(II), Rh(III) and Co(III) complexes, porphyrins and uranyl salts, in the presence of biological macromolecules such as DNA, have been the focus of increasing research work. The interest in such coordination compounds stems from their easily tunable properties. Not only their size and shape but also their... 

The reaction of uranyl salts with 2,2 -bisbenzoxaline gave a seven-co-ordinate species [U02L(H20)], in which L is the ligand (7) L, and the water... 

The ammino-uranyl salts unite readily with ether, and many of the compounds described have not been obtained entirely free from ether, which appears to be united with the compounds in much the same manner as water of hydration in salts.4... 

It can be prepd as a trihydrate salt by precipitating a uranyl salt with KOH and drying the product at 100°... 

In 1867 Bequerel postulated two types of afterglow based on his investigations of uranyl salts one with exponential and the other with hyperbolic decay. 

On rapid heating, oxalic add decomposes to formic acid, carbon monoxide, carbon dioxide, and water (qv). In aqneons solution, it is decomposed by uv. x-ray, or y-radiation with the liberation of carbon dioxide. Photodecomposition also occurs in the presence of uranyl salts. 

IJmnate. Sodium uranate, uranium yellow, Na2U04, yellow solid, insoluble, formed by reaction of soluble uranyl salt solution and excess sodium carbonate solution. Used (1) in the manufacture of yellowish-green fluorescent glass, (2) in ceramic enamels, (3) as a source of uranium for chemical reactions. 

Ciusa Oreste(Ref 2) prepd numerous metallic salts of 2-Nitrobenzene-isodiazonium Hydroxide and found the Ni,Cu,F JAl,Cd,Co uranyl salts defgr when heated, while the Co Cd salts expl when treated with coned sulfuric acid Refs l)Beil 16,480 482 483,(356,357 358)... 

Nielsen PE, Jeppesen C, Buchardt 0 (1988) Uranyl salts as photochemical agents for cleavage of DNA and probing of protein-DNA contacts. FEBS Lett 235 122-124... 

Petkovic, D.M. Kopecni, M.M. Mltrovic, A.A. Solvent extraction of nitric, hydrochloric and sulfuric acid and their uranyl salts with tri-n-octylphosphine oxide, Solvent Extr. Ion Exch. 10 (1992) 685-696. 

U(VI). This occurs only in uranyl salts containing the U022+ cation, which are outside the scope of this work. 

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