B. F. Myasoedov

[DIALKYLCARBAMOYLMETHYL] PHOSPHINE OXIDES ON THEIR EXTRACTION CAPACITY AND SELECTIVITY

ABSTRACT Extraction of Am ( III), Pu( IV), U( VI) from nitric acid solutions by dialkyl ( aryl) [ dialkylcarbamoylmethyl] phosphine oxides of different structures has been studied. The nature of substituents at phosphorus and nitrogen atoms and in methylene bridge affects extraction capacity, solubility and selectivity of reagents. The increase in extraction capacity of reagents with respect to Am, U, Pu and decrease in solubility and selectivity at consecutive replacement of alkyl-( or alkoxy-) radicals at phosphorus atom by phenyl ones was found. The advantage of reagents usage with two different radicals one of which is phenyl at phosphorus atom has been shown. The nature of substituent at nitrogen atom affect solubility but does not practically affect extraction capacity of reagent.

POLY-(DIPHENYLPHOSPHINYLMETHYL)ARENES - NEW ORGANOPHOSPHORUS EXTRACTANTS OF TRANS-PLUTONIUM ELEMENTS

The extraction properties of poly-(diphenylphosphinylmethyl)arenes in which the fragments of different methyl substituted aromatic compounds serve as hard bridges connecting the P=O functional groups was studied. The extraction of trivalent transplutonium elements and rare earth elements, uranium(VI), plutonium(IV) by chloroform solutions of these reagents as function of HNO/sub 3/ and ligands concentration was investigated. The selectivity of reagents was found to depend only on mutual arrangement of P=O groups in the bridge regardless of their number. Conformational analysis of the reagents described have been used to establish their structure and cause of their selectivity with respect to one or another element. 8 figures, 2 tables.

EXTRACTION OF TRANSPLUTONIUM ELEMENTS WITH DIPHENYL (ALKYL)DIALKYL- CARBAMOYLMETHYL PHOSPHINE OXIDES

Polydentate neutral organophosphorus compounds attract great interest as efficient extractants of transplutonium elements(TPE) from acid waste nuclear fuel element solution. With the view of a further search, reagents R′R″-PO-CH2-CNO-R2″ were synthetized and investigated. The solubility of R2′POCH2CNOR2″ vas investigated in organic solvents and in nitric acid solutions. This reagent was found to be the best one.

Extraction of technetium(VII) by calix[4]arene tetraketones and tetraesters from acidic and basic media

Tetrasubstituted on the lower rim calix[4]arenes, containing carbonyl and ester groups, and existing in a cone conformation are selective and efficient extracting agents for TcVII extraction from both acidic and basic solutions.

CORRELATION ANALYSIS OF ARYLIC STRENGTHENING OF THE EXTRACTION CAPACITY OF BIDENTATE ORGANOPHOSPHORUS EXTRACTANTS

This paper is devoted to the so-called effect of “anomalous arylic strengthening” (AAS) observed upon extraction of a series of elements, mainly actinides and lanthanides, by bidentate neutral organophosphorus compounds (BNOPC). This “anomalous” effect is an increase in the extraction capacity of a reagent when alkyl substituents at the phosphorus atom are replaced with more electronegative aryl groups. The influence of phenyl substituents at the phosphorus atom on the reactivity of organophosphorus compounds of various types was considered. Based on the data on electronic effects of substituents, hypotheses were formulated about the reasons for AAS involving phenyl groups that are biphilic because they have substituents capable of manifesting both donor and acceptor properties depending on several factors such as,e.g., the nature of the reaction center, the character of the attacking reagent, the nature of the solvent,etc. When a strong complex of a metal with a phenyl substituted reagent of BNOPC is formed during extraction, the phenyl groups become donating, and additional strengthening of the complex appears.

Oxides of dialkyl(diaryl)[dialkylcarbamoylmethyl]phosphines

Conclusions1.Oxides of dialkyl(diaryl)[dialkylcarbamoylmethyl]phosphines have been synthesized and characterized.2.The character of the substituents on the phosphorus atom substantially influences the extraction properties of the compounds obtained with respect to Am(III), the p-phenyl-substituted derivatives being most effective.

Poly(diphenylphosphinylmethyl) arenes, organophosphorus extractants for transplutonium elements

Conclusions1.New diphenylphosphinylmethyl substituted arenes, derivatives of benzene, naphthalene, and dibenzo-18-crown-6 have been synthesized.2.The extraction properties of these ligands having limited conformational mobility have been studied relative to tervalent transplutonium elements, europium, and sexivalent uranium.3.It has been shown that the extraction selectivity is dependent on the relative position of the coordination centers in the aromatic nucleus.