Bismuth Oxide Nitrite

A unique method for the degradation of 17-hydroxy-20-oxygenated pregnanes to 17-ketoandrostanes involves the photolysis of the corresponding nitrite esters.While this generally is equivalent to bismuthate or periodate oxidations, it is the only mild method for the conversion of a 17-hydroxy-... 

Heating with the following solids, their fusions, or vapours (a) oxides, peroxides, hydroxides, nitrates, nitrites, sulphides, cyanides, hexacyano-ferrate(III), and hexacyanoferrate(II) of the alkali and alkaline-earth metals (except oxides and hydroxides of calcium and strontium) (b) molten lead, silver, copper, zinc, bismuth, tin, or gold, or mixtures which form these metals upon reduction (c) phosphorus, arsenic, antimony, or silicon, or mixtures which form these elements upon reduction, particularly phosphates, arsenates,... 

Atomic hydrogen is a powerful reducing agent, even at room temperature. For example, it reacts with the oxides and chlorides of many metals, including silver, copper, lead, bismuth, and mercury, to produce the free metals. It reduces some salts, such as nitrates, nitrites, and cyanides of sodium and potassium, to the metallic state. It reacts with a number of elements, both metals and nonmetals, to yield hydrides such as NH3, NaH, KH, and PH3. Sulfur forms a number of hydrides the simplest is H2S. Combining with oxygen, atomic... 

The bismuth phosphate process consisted of a number of steps in which plutonium is made alternatively soluble and insoluble. Fuel elements containing plutonium, uranium, and fission products were first dissolved in nitric acid. Plutonium was reduced to the tetravalent state by addition of sodium nitrite. Plutonium phosphate Pu3 (P04)4 was coprecipitated with bismuth phosphate BiP04, by addition of bismuth nitrate and sodium phosphate. Coprecipitation of uranium was prevented by the presence of sufficient sulfate ion to form anionic UO2(804)2. The BiP04 precipitate was redissolved in nitric acid and subjected to two decontamination cycles to purify the plutonium. In each cycle the plutonium was oxidized to the soluble hexavalent state by NaBiOs or other strong oxidant. Next bismuth phosphate was again precipitated, to remove fission products while hexavalent plutonium remained in solution. Then plutonium was reduced to the tetravalent state and again coprecipitated with bismuth phosphate. 

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