caa a22 4500 378878409 CHVBK 20180305123426.0 cr unu---uuuuu 161128e20031201xx s 000 0 eng 10.1524/ract.91.12.729.23427 doi (NATIONALLICENCE)gruyter-10.1524/ract.91.12.729.23427 Extraction of the uranyl ion with 3-phenyl-4-benzoyl-5-isoxazolone (HPBI) and neutral donors from dilute nitric acid medium [Elektronische Daten] [S. Banerjee, A. Bhattacharyya, P. K. Mohapatra, S. Basu, V. K. Manchanda] The extraction behaviour of Uranium (VI) from aqueous nitric acid medium employing 3-phenyl-4-benzoyl-5-isoxazolone (HPBI) has been studied in the presence of various amides, e.g , di-2-ethylhexylacetamide (D2EHAA), di-2-ethylhexylpropanamide (D2EHPrA), di-2-ethylhexylisobutylamide (D2EHiBA) and di-2-ethylhexylpivylamide (D2EHPvA) in toluene medium. The extraction constant (log kex) for the binary species UO2(PBI)2·nH2O was found to be 1.42±0.14 which is by far the largest amongst the corresponding values known for the other β-diketones. The overall equilibrium constant (log K) for the ternary species UO2(PBI)2·D2EHAA, UO2(PBI)2·D2EHPrA, UO2(PBI)2·D2EHiBA and UO2(PBI)2·D2EHPvA were estimated to be 6.51, 6.21, 6.11 and 5.77 respectively. This trend in equilibrium constants was in accordance with the substitution of the amides as sterically crowded amides show relatively lower equilibrium constant values. The extraction constants follow an inverse correlation with the pKa values of the β-diketonates while the equilibrium constants vary linearly with the size of the amides. The steric factors have been found to play a significant role in the co-ordination of the amides to the uranyl β-diketones when the carbonyl group is a part of the heterocyclic ring. The distribution ratios of the metal were measured in the temperature range 15 to 52 °C using each of the amide donors in combination with HPBI. Calculation of enthalpy and entropy therefrom indicated that the extraction was thermodynamically favoured process and maximum extraction resulted in the case of UO2(PBI)2·D2EHAA. © 2003 Oldenbourg Wissenschaftsverlag GmbH Laboratory techniques, experiments nationallicence Analytical chemistry nationallicence Inorganic chemistry nationallicence Banerjee S. aut Bhattacharyya A. aut Mohapatra P. K. aut Basu S. aut Manchanda V. K. aut Radiochimica Acta/International journal for chemical aspects of nuclear science and technology Oldenbourg Wissenschaftsverlag GmbH 91/12/2003(2003-12-01), 729-736 0033-8230 91:12/2003<729 2003 91 ract https://doi.org/10.1524/ract.91.12.729.23427 text/html Onlinezugriff via DOI 1 research article jats NATIONALLICENCE 856 40 https://doi.org/10.1524/ract.91.12.729.23427 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Banerjee S. aut NATIONALLICENCE 700 1- Bhattacharyya A. aut NATIONALLICENCE 700 1- Mohapatra P. K. aut NATIONALLICENCE 700 1- Basu S. aut NATIONALLICENCE 700 1- Manchanda V. K. aut NATIONALLICENCE 773 0- Radiochimica Acta/International journal for chemical aspects of nuclear science and technology Oldenbourg Wissenschaftsverlag GmbH 91/12/2003(2003-12-01), 729-736 0033-8230 91:12/2003<729 2003 91 ract CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-gruyter