Extraction of ternary complexes of thorium(IV) with 3-phenyl-4-benzoyl-5-isoxazolone and neutral donors from nitric acid medium

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• 作者：Thakur ; P. ; Veeraraghavan ; R. ; Mohapatra ; P.K. ; Manchanda ; V.K. ; Dash ; K.C.
• 关键词：Extraction ; HPBI ; Thorium(IV)
• 刊名：Talanta
• 出版年：1996
• 出版时间：August, 1996
• 年：1996
• 卷：43
• 期：8
• 页码：1305-1312
• 全文大小：528 K

文摘

The extraction behaviour of thorium(IV) from aqueous nitric acid employing 3-phenyl-4-benzoyl-5-isoxazolone (HPBI) in the presence of tri-n-octyl phosphine oxide (TOPO) as well as tri-n-butyl phosphate (TBP) in xylene medium was investigated. The extraction constant (log k_ex) for the binary organic phase species Th(PBI)₄ was determined to be 8.26 which is by far the largest amongst the corresponding values known for other 46;-diketones. The overall extraction constant (log K) for the ternary species Th(PBI)₄·TBP and Th(PBI)₄·2TOPO were estimated to be 14.96 and 20.96 respectively. An inverse correlation of the adduct formation constant (log K_s) with the pK_a of the 46;-diketones, 2-thenoyltrifluoroacetone, 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone and HPBI, was observed. The steric as well as the electronic effects of adduct formation have been discussed. Analytical application of HPBI for the separation of ²³⁴Th radiotracer from natural uranium (99.3 % ²³⁸U) has been suggested.