Uranium adducts

MIBK is a highly effective separating agent for metals from solutions of their salts and is used in the mining industries to extract plutonium from uranium, niobium from tantalum, and zirconium from hafnium (112,113). MIBK is also used in the production of specialty surfactants for inks (qv), paints, and pesticide formulations, examples of which are 2,4,7,9-tetramethyl-5-decyn-4,7-diol and its ethoxylated adduct. Other appHcations include as a solvent for adhesives and wax/oil separation (114), in leather (qv) finishing, textile coating, and as a denaturant for ethanol formulations. 

Complexes. The structure of an n a charge-transfer complex between quinoxaline and two iodine atoms has been obtained by X-ray analysis and its thermal stability compared with those of related complexes. The hydrogen bond complex between quinoxaline and phenol has been studied by infrared spectroscopy and compared with many similar complexes. Adducts of quinoxaline with uranium salts and with a variety of copper(II) alkano-ates have been prepared, characterized, and studied with respect to IR spectra or magnetic properties, respectively. 

Uranium(IV) chloride adducts of Ph2SO have been isolated (73) of the type [U(Ph2S0)2Cl4]-nH20, and infrared measurements show the sulfoxide to be O-bonded. Analogous complexes of diphenyl sulfone could not be synthesized (251). 

Many uranium(VI) sulfoxide complexes of the type [U02X2(Me2S0)B] (X = anionic ligand) have been synthesized, including chloride, bromide (322, 323), nitrate (41), and acetate (431) adducts. The thiocyanate (113,114) and selenocyanate (292) adducts [U02(XCN)2(Me2SO)2] have been synthesized, and infrared data indicate the presence of O-Me2SO and JV-NCX ligands. 

The green phosphoric acid from a phosphoric acid plant (PAP) contains 25-30% H3PO4. The acid is heavily entrained with impurity cations, among which arsenic, cadmium, and uranium are the most toxic. In addition, anions, like chloride, fluoride, and sulfate must be considered. Selective extraction of phosphoric acid [18] as an adduct complex with TBP according to the block diagram in Fig. 14.12 has been used to produce acid of food grade. 

LEWIS BASE ADDUCTS OF URANIUM TRIIODIDE AND TRIS[BIS(TRIMETHYLSILYL)AMIDO) URANIUM ... 

Some authors consider that the extracted complex is best formulated as an adduct, such as [(RjNH)2S04]2, U02S04(H20)3, which is the stoichiometry suggested by Sato on the basis of the analysis of solutions of tri- -octylamine saturated with uranium.204 Further studies of the extraction of uranium from sulfate media by amine salts have been reviewed by Cattrall and... 

Lin, Y. Wu, H. Smart, N. Wai, C.M. Investigation of adducts of lanthanide and uranium P-diketonates with organophosphorus Lewis bases by supercritical fluid chromatography, J. Chrom. A 793 (1998) 107-113. 

Alkali, alkaline earth, and a number of transition metals are not extracted by this complex into SC-C02.49 Similarly, experiments examining the behavior of various FP oxides (e.g., Zr02, Mo03, Ru02, and CeOj) under the same conditions have led to the conclusion that with the exception of Nd, decontamination factors of 400 or more (vs. uranium) can be readily obtained for all common FP elements.53 The TBP-nitric acid adduct thus exhibits significant extraction selectivity for uranium. 

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