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Туранов, А. Н.; Карандашев, В. К.; Kharitonov, A. V.; Safronova, Z. V.; Yarkevich, A. N.

doi:10.1023/a:1014866932427

Cited by 8 publications

(8 citation statements)

References 3 publications

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“…A similar trend is observed in REE extraction with tetraphenylethylenediphosphine dioxide VI and its a-alkyl-substituted analog VII (Fig. 3); it was noted previously in the systems with ethylenediphosphine dioxides in 1,2-dichloroethane [28]. Indeed, with respect to participation of functional groups in complexation with an REE ion, compound V can be considered either as CMPO [in this case the inductive effect of the CH 2 P(O)Ph 2 group is still stronger than in IV] or as ethylenediphosphine dioxide with the C(O)NBu 2 substituent in the a-position of the ethylene bridge.…”

Section: Resultssupporting

confidence: 88%

“…3). Such a trend was also noted for other substituted ethylenediphosphine dioxides [28]. In the system with V, the distribution factors of Am and La3Eu are higher than in the system with VII, whereas those of Gd3Lu are lower (Fig.…”

Section: Resultssupporting

confidence: 71%

“…These data suggests that cerium-group REEs and Am are coordinated with V via P=O and C=O groups, whereas complexation with yttrium-group REEs occurs via two P=O groups linked with an ethylene bridge. It should be noted that the difference in the REE extraction constants with tetraphenylmethylenediphosphine dioxide and substituted ethylenediphosphine dioxides decreases with increasing Z [28], i.e., yttrium-group REEs show greater tendency to form seven-membered chelate rings. Since replacement of the alkyl group in VII by the C(O)NBu 2 group (compound V) somewhat decreases the extrac- tion of yttrium-group REEs (Fig.…”

Section: Resultsmentioning

confidence: 99%

“…Compounds I!III [19], VI [20], and VII [21] were prepared by published procedures; synthesis of IV and V is described in this paper. Compound IV was prepared as shown below from diester VIII via dicarboxylic acid IX; compound V was prepared by direct amination of the corresponding ester.…”

Section: Methodsmentioning

confidence: 99%

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Extraction of U(VI), Th(IV), Pu(IV), Am(III), and rare-earth elements from nitric acid solutions with diphenyl(dialkylcarbamoylmethyl)phosphine oxides substituted in the methylene bridge

et al. 2004

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The extractive power and selectivity of diphenyl(dialkylcarbamoylmethyl)phosphine oxides in extraction of U(VI), Th(IV), Pu(IV), Am(III), and rare-earth elements from nitric acid solutions was studied, as influenced by substitution of one or two hydrogen atoms in the methylene bridge with alkyl, cycloalkyl, CH 2 P(O)Ph 2 , and CH 2 C(O)NBu 2 groups. Diaryl(dialkylcarbamoylmethyl)phosphine oxides (CMPOs) are powerful extractants of transplutonium (TPE) and rare-earth (REE) elements from nitric acid solutions. The relationship between the structure and extractive power of these reagents was extensively studied [1312]. It was found that extraction of Am(III) from nitric acid solutions substantially increased on replacement of alkyl substituents at the P atom by aryl groups [2,3,9]. Possible causes of this effect were discussed in numerous papers [13317]. Replacement of alkyl groups by phenyl groups at the N atom, on the contrary, results in decreased extraction of Am(III) [10]. The structure of alkyl substituents at the N atom in CMPO molecules affects the distribution factors of U(VI), Pu(IV), and Am(III) weakly but differently, which results in different separation factors. The reagents with long or branched substituents are the most selective [12]. Introduction of an alkyl substituent into the methylene bridge of a CMPO molecule increases the solubility of the reagent in organic solvents and its extraction capacity [8], enhances the selectivity of extraction of U(VI) and Pu(IV) relative to Am(III), but does not affect the separation factor of Am(III) and Eu(III) [7].The majority of these studies were made with 1,2-dichloroethane as organic diluent. At the same time, with more polar diluents, extraction of Am(III) with a series of CMPOs increases [18]. For example, fluorinated nitroaromatic compounds such as m-nitrobenzotrifluoride (Fluoropol) ensure both high solubility of CMPOs and their extractable complexes with metal ions in the organic phase and the higher distribution factors, compared to other known diluents [18]. It was of interest to examine the effect of substituents in the methylene bridge of the CMPO molecule on the extractive power and selectivity of reagents in systems with highly polar diluents. For this purpose, we examined in this work some trends in the distribution of U(VI), Th(IV), Pu(IV), Am(III), and REEs between nitric acid solutions and solutions of CMPOs of various structures in Fluoropol. We studied diphenyl(dialkylcarbamoylmethyl)phosphine oxides Ia and Ib with butyl and isobutyl substituents at the N atom and their derivatives substituted in the methylene bridge: IIa!IId (alkyl substituents) and IIIa!IIIc (cyclic derivatives). We also prepared and studied CMPOs IV and V containing additional complexing sites in the same molecule. We compared the extractive powers of CMPO V and its closest diphosphoryl analogs containing no carbamoyl group: tetraphenylethylenediphosphine dioxide VI and 1,2-bis(diphenylphosphinyl)octane VII.

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Section: Resultssupporting

confidence: 88%

Section: Resultssupporting

confidence: 71%

Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

See 2 more Smart Citations

Extraction of U(VI), Th(IV), Pu(IV), Am(III), and rare-earth elements from nitric acid solutions with diphenyl(dialkylcarbamoylmethyl)phosphine oxides substituted in the methylene bridge

et al. 2004

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“…For this reason, a-alkyl-substituted dialkylamides of diphenylphosphinoylacetic acid are usually prepared starting from potassium derivatives of corresponding dialkylamides [1] or preliminary synthesized a-alkyl-substituted diphenylphosphinoylacetic acids [2]. In the present work we studied feasibility of direct dialkylaminomethylation of certain ÄÄÄÄÄÄÄÄÄÄÄÄ dialkylamides of diphenylphosphinoylacetic acid for preparing complex-forming agents of a new type.…”

mentioning

confidence: 99%

Synthesis and Extractive Properties of Dialkylaminomethyl-substituted Dialkylamides of Diphenylphosphinoylacetic Acid

2005

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Dialkylamides of diphenylphosphinoylacetic acids, dialkylaminomethyl-substituted by the methylene group, were prepared by means of the Mannich reaction from diphenyl(dialkylcarbamoylmethyl)-phosphine oxides or by reaction of the latter compounds with tetraethylmethylenediamine. Extractive ability of the obtained compounds toward U(VI) and Pd(II) in nitrate media was studied.Alkylation of dialkylamides of diphenylphosphinoylacetic acid by the methylene group is most commonly complicated by the low CH acidity of methylene protons. For this reason, a-alkyl-substituted dialkylamides of diphenylphosphinoylacetic acid are usually prepared starting from potassium derivatives of corresponding dialkylamides [1] or preliminary synthesized a-alkyl-substituted diphenylphosphinoylacetic acids [2]. In the present work we studied feasibility of direct dialkylaminomethylation of certain ÄÄÄÄÄÄÄÄÄÄÄÄ dialkylamides of diphenylphosphinoylacetic acid for preparing complex-forming agents of a new type.Ethyl (diethoxyphosphinoyl)acetate whose methylene protons exhibit enhanced acidity due to the electron-acceptor effect of the ethoxycarbonyl group reacts with Formalin and diethylamine under Mannich reaction conditions to form a condensation product, diethyl 2,4-bis(diethoxyphosphinoyl)pentane-1,5-dioic acid [3]. (EtO) 2 P(O)CH 2 C(O)OEt + Et 2 NH + CH 2 O 76 (EtO) 2 P(O)CHC(O)OEt g CH 2 g (EtO) 2 P(O)CHC(O)OEt ÄÄÄÄÄÄÄÄÄÄÄÄ Unlike ethyl (diethoxyphosphinoyl)acetate, N,N-dialkyl(diphenylphosphinoyl)acetamides Ph 2 P(O)CH 2 .

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