Tributyl phosphate complexes

Although tellurium tetrachloride has been reported55 to form a 1 2 complex with acetamide, there appears to be little other information available on the complex. Similarly, the reported tributyl phosphate complex of polonium tetrachloride56 has received little attention. The formation of a polonium(IV) perchlorate complex with tributyl phosphate has been suggested57 in the solvent extraction of polonium from perchloric acid. 

CJ. Hartzell et al., Molecular modeling of the tributyl phosphate complex of europium nitrate in the clay hectorite. J. Phys. Chem. A 102, 6722-6729 (1998)... 

Hartzell CJ, Cygan RT, Nagy KJ (1998) Molecular Modeling of the Tributyl Phosphate Complex of Europium Nitrate in the ( lay Hectorite, J Phys Chem A 102(34) 6722-6729... 

Uranyl dinitrate Tributyl phosphate Complex U02(N03)2- 2(Ci2H2704P) 926.67 U-6, U-7... 

Uranyl thenoyltrifluoroacetylacetonate Tributyl phosphate complex U02-(CioH6- F303S)2- 2(Ci2H2704P) 1329.09 U-8... 

Supercritical Fluid Extraction of Plutonium and Americium from Soil Using p-Diketone and Tributyl Phosphate Complexants... 

Den Auwer et al. (1999) applied XAES to the structural analysis of TBP (Tributyl phosphate) complexes of tetra- and hexavalent U, Np, and Pu. Similar to the results of hydrated Pu complexes, they observed significant difference in the XANES spectra between the Pu " and Pu02 species as shown in Fig. 18.29. However, the XANES spectra of An02(N03)2(TBP)2 (An = U, Np, Pu) solution complexes show no significant difference among them. 

Haile JM (1997) Molecular E namics Simulation Elementary Methods. John Wiley and Sons, New York Hartzell CJ, Cygan RT, Nagy KL (1998) Molecular modeUng of the tributyl phosphate complex of europium nitrate in the clay hectorite. J Phys Chem A 102 6722-6729 Hass KC, Schneider WF, Curioni A, Andreoni W (1998) The chemistry of water on alumina surfaces Reaction dynamics from first principles. Science 282 265-268 Hazen RH (1976) Effects of temperature and pressiue on the cell dimension and X-ray temperature factors of periclase. Am Mineral 61 266-271... 

In TBP extraction, the yeUowcake is dissolved ia nitric acid and extracted with tributyl phosphate ia a kerosene or hexane diluent. The uranyl ion forms the mixed complex U02(N02)2(TBP)2 which is extracted iato the diluent. The purified uranium is then back-extracted iato nitric acid or water, and concentrated. The uranyl nitrate solution is evaporated to uranyl nitrate hexahydrate [13520-83-7], U02(N02)2 6H20. The uranyl nitrate hexahydrate is dehydrated and denitrated duting a pyrolysis step to form uranium trioxide [1344-58-7], UO, as shown ia equation 10. The pyrolysis is most often carried out ia either a batch reactor (Fig. 2) or a fluidized-bed denitrator (Fig. 3). The UO is reduced with hydrogen to uranium dioxide [1344-57-6], UO2 (eq. 11), and converted to uranium tetrafluoride [10049-14-6], UF, with HF at elevated temperatures (eq. 12). The UF can be either reduced to uranium metal or fluotinated to uranium hexafluoride [7783-81-5], UF, for isotope enrichment. The chemistry and operating conditions of the TBP refining process, and conversion to UO, UO2, and ultimately UF have been discussed ia detail (40). 

Di-n-amyl n-amylphosphonate [6418-56-0] M 292.4, b 150-151°/2mm, n 1.4378. Purified by three crystns of its uranyl nitrate complex from hexane (see tributyl phosphate). Extracts Zr " from NaCl solns. 

The separation of basic precipitates of hydrous Th02 from the lanthanides in monazite sands has been outlined in Fig. 30.1 (p. 1230). These precipitates may then be dissolved in nitric acid and the thorium extracted into tributyl phosphate, (Bu"0)3PO, diluted with kerosene. In the case of Canadian production, the uranium ores are leached with sulfuric acid and the anionic sulfato complex of U preferentially absorbed onto an anion exchange resin. The Th is separated from Fe, A1 and other metals in the liquor by solvent extraction. 

Spectrophotometric methods may often be applied directly to the solvent extract utilising the absorption of the extracted species in the ultraviolet or visible region. A typical example is the extraction and determination of nickel as dimethylglyoximate in chloroform by measuring the absorption of the complex at 366 nm. Direct measurement of absorbance may also be made with appropriate ion association complexes, e.g. the ferroin anionic detergent system, but improved results can sometimes be obtained by developing a chelate complex after extraction. An example is the extraction of uranyl nitrate from nitric acid into tributyl phosphate and the subsequent addition of dibenzoylmethane to the solvent to form a soluble coloured chelate. 

Lanthanum also may be separated from aqueous solutions of rare-earth nitrates by liquid-hquid extraction using a suitable water-immiscible organic hquid such as tributyl phosphate or another complexing agent dissolved in it. 

Complexes with organic compounds have been reported. Solubility studies with tributyl phosphate (TBP) indicate the formation of a complex PoC14-2TBP (IS). Weighable amounts of polonium tetrachloride in dilute hydrochloric acid can be titrated to a colorless end point with ethylene-diamine tetra-acetic acid (EDTA) the results suggest a complex with two molecules of EDTA, but solubility studies favor a 1 1 complex. The EDTA complex is soluble in alkali and is more stable in alkaline than in acid media, but the ligand is rapidly destroyed by the radiation and solvent radiolysis products 12). However, EDTA can apparently be used to complex trace polonium in the separation of radium D-E-F mixtures (129). 

Hahn, H.T., Vander Wall, E.M. 1964. Complex formation in the dilute uranyl nitrate-nitric acid-dibutyl phosphoric acid-tributyl phosphate-amsco system. J. Inorg. Nucl. Chem. 26 191-192. 

Zhang, P., Kimura, T. 2006. Complexation of Eu(III) with dibutyl phosphate and tributyl phosphate. Solvent Extr. lonExch. 24 149-163. 

Stieglitz, L. 1971. Investigation on the nature of degradation products in the system 20 vol.-% tributyl phosphate-dodecane-nitric acid. I. Enrichment of complexing products and infra-red study. Proceedings of the International Solvent Extraction Conference, 19-23 April, Society of Chemical Industry London, Vol. I, 155-159. 

Finally, PSPs based on the OEP metal complexes in various cellulose derivative polymers also have been introduced. Cellulose derivative polymers such as ethyl cellulose, cellulose acetate etc., as shown in Fig. 9, also provide a mechanical strength to thin film. The oxygen permeability, diffusion constant, and solubility for oxygen for typical cellulose derivative polymers are listed in Table 1. Cellulose derivative polymer films with plasticizer tributyl phosphate (TBP) have large oxygen permeability. Cellulose acetate with TBP... 

Raman spectral studies of the species MX(n" 2) (n = 2—4 M = Zn, Cd, or Hg X = Cl, Br, or I) in anhydrous tributyl phosphate have been reported.24 For the MX2 molecules, sufficient metal dihalide-solvent interaction exists to suggest bent X—M—X species with C2v rather than >ooh symmetry. The effect appears most marked for zinc(n) and least marked for mercury(n), which is in accord with the Lewis acidity sequence ZnX2 > CdX2 > HgX2. A similar analysis of the anionic MX3 complexes formed from a 1 1 mixture of LiX and MX2 again demonstrates solvent interaction, and a tetrahedral C3v species is indicated, rather than the planar structure found in the solid state. Studies involving the halogeno-complexes of zinc, cadmium, and mercury in DMSO and DMF have also been reported.25,26... 

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