Uranium ethoxide

BORONCOMPOUNDS - BORONHYDRIDES, HETEROBORANES AND THEIRMETALLADERIVATIVES] (Vol 4) Aluminum uranium ethoxide [64653-66-3]... 

Tetrakis(ethylthio)uranium, 3096 Titanium butoxide, 3730 Titanium(III) methoxide, 1317 Titanium tetraisopropoxide, 3579 Tungsten hexamethoxide, 2604 Zinc ethoxide, 1704... 

U(OEt)5 is easily prepared by oxidation of U(OEt)4 by bromine in ethanol, followed by addition of the calculated quantity of sodium ethoxide, a reaction which yields181 only Np(OEt)4Br in the case of Np(OEt)4. U(OEt)s is commonly used as the starting material for the preparation of other uranium(V) alkoxides by alcohol exchange reactions. A comprehensive review of metal alkoxides includes a useful discussion of the uranium(V) compounds.182... 

Tetrakis(ethylthio)uranium, 3090 Titanium butoxide, 3724 Titanium tetraisopropoxide, 3573 Titanium(III) methoxide, 1313 Tungsten hexamethoxide, 2600 Zinc ethoxide, 1698... 

Scheme 10). In this compound one pyrrole ring was isomerized by shifting the attachment of the chain from the a- to the (3-position GV-confused) while the formal tetravalent oxidation state is provided by the presence of the ethoxide group. The origin of the LiOEt unit is the result of a one-electron attack on thf followed by H abstraction, which accounts for the tetravalent state of uranium in the product. 

Alkoxide complexes. In contrast to the propensity of many uranium(V) species to disproportionate to uranium(IV) and uranium(VI), homoleptic uranium(V) alkoxide compounds are quite stable toward disproportionation. Gilman and co-workers reported the synthesis of dark brown uranium(V) pentakis(ethoxide) from a metathesis reaction between UCI4 and four equivalents of sodium ethoxide. . In this early report, it was noted that better yields were obtained when no great care was taken to exclude air from the reaction, and in the presence of oxygen, the product yield was 80%. The mechanism shown in Equations (36) and (37) was suggested for this reaction. 

In the following procedures, /3-uranium pentafluoride is conveniently prepared by the photochemical reduction of uranium hexafluoride, in a manner similar to an earlier smaller-scale preparation.9 Pentaethoxyuranium is prepared directly from 0-UFs and sodium ethoxide in ethanol. The preparation of hexafluoro-uranium salts from /3-UFs in nonaqueous solvents is described in a procedure that avoids the use of hydrofluoric acid common to previous methods.10,11... 

The receiver flask is now heated on an oil bath and the contents are subjected to a vacuum distillation. At first, with the bath temperature as high as 140°C and at 5-10 mm., the last of the alcohol is removed the uranium (VI) ethoxide distills out at the same bath temperature but at a high vacuum (0.003 mm.). Yield 20 g. Rectification in high vacuum affords the pure product. Yield 16 g. (43%). The boiling point is 72-74°C at 0.001 mm. 

Red, mobile liquid d 1.563. Monomeric in benzene. Readily soluble in benzene, ether, petroleum ether, etc. Extremely sensitive to moisture forms uranyl hydroxide when hydrolyzed. Strong oxidizing agent. Readily reduced to uranium (V) ethoxide. Syn-proportionates with U (IV) ethoxide according ... 

Alternatively when uranium tetraethoxide was treated with bromine in 2 1 molar ratio followed by the addition of 2 moles of sodium ethoxide, uranium pentaethoxide... 

It was also observed that uranium pentaethoxide was suceptible to oxidation by air or molecular oxygen to give uranium hexaethoxide, but the yield of the product was very poor. Gilman et al found that better yields were obtained by oxidizing the double ethoxide of sodium and uranium, NaU(OEt)6, in place of uranium pentaethoxide, U(OEt)5, with bromine, lead tetraacetate or benzoyl peroxide the yields in these reactions were 5-10, 20, or 40-60%, respectively ... 

Karraker measured the electronic absorption spectrum of dimeric uranium penta-ethoxide and the weak narrow bands observed at 5405, 5680, 6622, 6934, 10200, 11 690, and 14 490 cm" have been assigned to f-f transitions for a distorted octahedral f system with a spin-orbit coupling constant of 1905 cm. ... 

In some cases, a control of stoichiometry allows the isolation of mixed alkoxide-phenoxide derivatives.In the case of uranium(v) ethoxide, only partial substitution can be achieved even by reacting with an excess of phenol. ... 

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