Uranium phosphorus complexes

Scheme 17 Synthesis of various uranium phosphorus complexes [236,238]...

Conflicting information has been pubUshed on the relative extents of extraction of U and UOj " by dioctyl pyrophosphate. The reduction of the feed acid, which is done in the commercial process, may serve mainly to minimize the coextraction of iron(III), which is extracted much more strongly than iron(II). The uranium(IV) complexes extracted by dialkyl pyrophosphate have been reported to be of the type U(R2HP20v)4, 2 and those of uranium(VI) to be of the type U02(R2P207). However, some doubt was subsequently cast on these conclusions when it was found that the dioctyl pyrophosphate used, which had been prepared by the action of octanol upon phosphorus pentoxide, was a complex mixture of products.Indeed, the strong extractive power of this reagent towards uranium(IV) appears to be the result of a fortuitous synergistic interaction between the components of the mixture. ... 

Scheme 24 Synthesis of uranium IV complexes fiom phosphorus ylides...

Although trialkyl- and triarylbismuthines are much weaker donors than the corresponding phosphorus, arsenic, and antimony compounds, they have nevertheless been employed to a considerable extent as ligands in transition metal complexes. The metals coordinated to the bismuth in these complexes include chromium (72—77), cobalt (78,79), iridium (80), iron (77,81,82), manganese (83,84), molybdenum (72,75—77,85—89), nickel (75,79,90,91), niobium (92), rhodium (93,94), silver (95—97), tungsten (72,75—77,87,89), uranium (98), and vanadium (99). The coordination compounds formed from tertiary bismuthines are less stable than those formed from tertiary phosphines, arsines, or stibines. 

Extraction by solvation involves the displacement of some or all of the water molecules in the coordination sphere of a metal complex by neutral organic donors, conferring high solubility in water-immiscible solvents. Solvating extractants are typically ethers, ketones, or neutral phosphorus(V) molecules containing P=0 units, e.g. the extraction of uranium(VI) from nitrate solutions by tri- -butyl phosphate (TBP). 

A unique complex has been recently reported with uranium bound to elemental phosphorus, (/u- , -P4)[U(NRAr)3]2 (R = t-Bu, Ar = 3,5-dimethylphenyl). The compound was prepared by reaction of the bivalent U(NRAr)3 with white phosphorus. 

PUC24H27, Uranium(IV), tris(n -cyclopenta-dienyl)[(dimethylphenylphosphoranyli-dene)methyl], 27 177 P2, Phosphorus, di-, molybdenum complex, 27 224... 

AETHYLALKOHOL (German) (64-17-5) Forms explosive mixture with air [flash point 55°F/13°C 68°F/20°C (80%) 72°F/22°C (60%) 79°F/26°C (40%)]. Reacts, possibly violently, with strong oxidizers, bases, acetic anhydride, acetyl bromide, acetyl chloride, aliphatic amines, bromine pentafluoride, calcium oxide, cesium oxide, chloryl perchlorate, disulfuryl difluoride, ethylene glycol methyl ether, iodine heptafluoride, isocyanates, nitrosyl perchlorate, perchlorates, platinum, potassium-tert-butoxide, potassium, potassium oxide, potassium peroxide, phosphorus(III) oxide, silver nitrate, silver oxide, sulfuric acid, oleum, sodium, sodium hydrazide. sodium peroxide, sulfinyl cyanamide, tetrachlorosilane, -tri-azine-2,4,6-triol, triethoxydialuminum tribromide, triethylaluminum, uranium fluoride, xenon tetrafluoride. Mixture with mercury nitrate(II) forms explosive mercury fulminate. Forms explosive complexes with perchlorates, magnesium perchlorate (forms ethyl perchlorate), silver perchlorate. Flow or agitation of substance may generate electrostatic charges due to low conductivity. 

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