Uranium pentaethoxide

Halstead, G. W. Eller, P. G. Asprey, L. B. Salazar, K. V. "Convenient Multi gram Synthesis of Uranium Pentafluoride and Uranium Pentaethoxide," Inorg. Chem., 1978, 17, 2967. 

There are other methods of synthesis of metal alkoxides. During the synthesis of uranium tetraethoxide, Gilman and co-workers ° observed that it could be oxidized by an oxidizing agent such as dry air to uranium pentaethoxide. The exact mechanism is not known but it is assumed that uranium(iv) is oxidized to uranium (v) the yield of product was only 65% ... 

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 ... 

Gilman and co-workers have also shown that interaction of uranium pentaethoxide and hydrogen chloride in appropriate molar ratios of reactants in ether afforded the products UCl(OEt)4, UCl2(OEt)3, and UCl3(OEt)2. 

The highest oxidation state (+6) appears not to be the most stable one for the alkoxides. Uranium hexaethoxide is easily converted into pentaethoxide on action of different reducing agents such as ethylmercaptane, diethylamine, and soon. Its interaction with uranium tetraethoxide leads to coproportionation [856] ... 

Jones era/. observed that uranium tetraethoxide reacted with bromine to yield uranium monobromide tetraethoxide which was then used for the preparation of the pentaethoxide (Section 2.10.1)... 

Penta(tropolonato)-protactinium and -uranium have been prepared using tropolone and the metal pentaethoxide in benzene. Uranium pentachloride reacts with an excess of tropolone in non-aqueous solvents to give chlorotetra(tropolonato)uranium. Enthalpies of formation of tri(tropolonato)- and tri(4-methyltropolonato)-aluminium (ill) have been determined at 298.15 K by solution calorimetry. The gas phase enthalpies of formation have been calculated and from these the A1—O bond energies derived. The crystal and molecular structure of a tetranuclear cobalt(ii)-tropolonate complex, [Co4(C7H502)s(H20)2] has been reported. Spectroscopic data (i.r., n.m.r.) of a mercury (ii) tropolonate indicates that it has an unsymmetrical structure with two approximately linear short Hg—O bonds and two longer ones. ... 

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