V. P. Morgalyuk

Simple route to secondary amides of phosphorylacetic acids and their use for extraction and sorption of actinides from nitric acid solutions

An efficient method for the synthesis of secondary alkylamides of phosphorylacetic acids (APA) was proposed. The method involves amidation of ethyl phosphorylacetates with primary aliphatic amines. The scope of reaction was determined. Reactions with ethylenediamine and 1,4-diaminobutane yield the corresponding bisamides; in the case of 1,3-diaminopropane, N-(3-aminopropyl)diphenylphosphorylacetamide or N,N′-propylenebis(diphenylphosphorylacetamide) was obtained, depending on the reaction conditions. The extraction of americium(III) complexes and the sorption of uranium(VI) by sorbents with physically sorbed APA from nitric acid solutions were studied. There is no correlation between the partition coefficient of americium(III) and the structure of APA; in the sorption of uranium(VI), the degree of extraction depends on the complexone structure.

Radiation resistance of a series of organophosphorus extractants

Extraction of U(VI), TUE, and REE from acid process solution with solutions of mono-and bidentate neutral organophosphorus compounds (NOPCs), phenyloctyl(N,N-diisobutylcarbamoylmethyl)phosphine oxide (CMPO), 2-ethylhexyl (N,N-dibutylcarbamoylmethyl)phenylphosphinate (CMPP), and unsymmetrical phosphine oxide (UPO) was studied as influenced by γ-irradiation at different absorbed dose rates. In all cases extraction of the target radionuclides decreased with increasing absorbed dose of γ-radiation. The resistance of the NOPCs to radiolysis decreases as CMPO>CMPP>UPO owing to the difference in the structures of their molecules.

Gadolinium(III) 3,5,5-trimethylhexanoate complexes for creation of stable Gd-loaded liquid organic scintillators

Optimal conditions have been found for the synthesis of a gadolinium 3,5,5-trimethylhexanoate complex for creation of stable Gd-loaded scintillators. Procedures for the preparation of gadolinium concentrates containing 10–20 g/L Gd in a linear alkylbenzene have been developed, and their stability has been studied. The structure of gadolinium complexes deposited from the concentrates prepared by extraction has been determined.

Stoichiometry of the reaction of diphenylchlorophosphine with dimethylformamide in the presence of NaI

Stoichiometric relations of initial compounds and reaction products in the synthesis of N,N-dialkyl-(diphenylphosphinomethylene)iminium are established; the second reaction product is diphenylphosphinic iodide. Bringing triphenylphosphine into the reaction increases the N,N-dialkyl(diphenylphosphinomethylene)-iminium yield approximately twice. One of the reaction intermediates is shown to be iododiphenylphosphine. The reaction can be regarded as disproportionation.

Extraction and sorption preconcentration of U(VI), Am(III), and Pu(IV) from nitric acid solutions with alkylenediphosphine dioxides

The extraction of U(VI), Am(III), and Pu(VI) from nitric acid solutions in the form of complexes with alkylenebis(diphenylphosphine) dioxides and their sorption with POLIORGS F-6 sorbent prepared by noncovalent immobilization of methylenebis(diphenylphosphine) dioxide (MDPPD) on a KhAD-7M™ polymeric matrix were studied. The preconcentration conditions and distribution coefficients of U(VI), Am(III), and Pu(IV) in their sorption from 3 M HNO3 were determined. The possibility of concentrating actinides from multicomponent solutions was demonstrated. The composition and nature of complexes of U(VI) with MDPPD were determined from the 31P NMR data.

Large-Volume Detector at the Baksan Neutrino Observatory for Studies of Natural Neutrino Fluxes for Purposes of Geo- and Astrophysics

At the Baksan Neutrino Observatory (Institute for Nuclear Research, Russian Academy of Sciences, Moscow) deployed in the Caucasus mountains, it is proposed to create, at a depth corresponding to 4760 mwe, a large-volume neutrino detector on the basis of a liquid scintillator with a target mass of 10 kt. The detector in question is intended for recording natural fluxes of neutrinos whose energy may be as low as 100MeV. Neutrino fluxes from various sources are considered in the present study, and the expected effect in the proposed detector is estimated. The detector hat is being developed at the Baksan Neutrino Observatorywill become part of the world network of neutrino detectors for studying natural neutrino fluxes.

A Scheme of the Stepwise Reaction of Diphenylchlorophosphine with N,N-Dialkylformamides in the Presence of NaI

On an example of DMF was proposed and experimentally verified stepwise reaction scheme of the reaction of diphenylchlorophosphine with N,N-dialkylformamides. The first stage is autocatalytic reaction of the synthesis of (diphenylphosphoryl)(N,N-dialkylamino)chloromethanes proceeding through the intermediate formation of diphenyldichloro[(N,N-dialkylamino)chloromethyl]phosphoranes. In the second stage that includes NaI, the (diphenylphosphoryl)(N,N-dialkylamino)chloromethanes are reduced by diphenyliodophosphine (or triphenylphosphine) to form the final N,N-dialkyl(diphenylphosphinomethylene)iminium iodides. One can assume that the reaction of the synthesis of N,N-dialkyl(diphenylphosphinomethylene)-iminium iodides proceeds in a similar way, starting with diphenyliodphosphine.

Synthesis of polyfunctionalized methylphosphine oxides

N,N-Dialkylamino(diphenylphosphoryl)chloromethanes, a new type of organophosphorus compounds, were synthesized. On dissolving in polar and low polar solvents, N,N-dialkylamino(diphenylphosphoryl)chloromethanes dissociate spontaneously with the P—C bond cleavage to form the diphenylphosphinite anion Ph2PO−. This was confirmed by the reaction of N,N-dimethylamino(diphenylphosphoryl)chloromethane with electrophilic substrates to form the corresponding addition or substitution products of Ph2PO−. The capability of spontaneous generating the diphenylphosphinite anion considers accessible N,N-dimethylamino(diphenylphosphoryl)chloromethane as a synthetic equivalent of the diphenylphosphinite anion.

Efficiency of different methods for removing U, Th, and K from a liquid scintillator

The efficiency of removing U and Th from a liquid organic scintillator based on linear alkylbenzene (LAB) by stripping with a 0.02 M aqueous solution of aminomethylenediphosphonic acid and by sorption on aluminum oxide and silica gel was studied. A procedure was developed for purification of scintillation additives (2,5-diphenyloxazole, 2-biphenyl-5-phenyloxazole, p-terphenyl) to remove 40K.

A procedure for removing uranium, thorium, and potassium-40 microimpurities from a liquid organic scintillator based on linear alkylbenzene

A procedure was developed for removing uranium, thorium, and potassium from a liquid organic scintillator based on linear alkylbenzene (LAB) by stripping with water. The volume ratio of the scintillator and water in the process should be no less than 1: 5. The attenuation length (L420) of LAB after treatment with water does not change and is as high as 13.0 ± 1.8 m. The solubility of water in LAB and of LAB in water was determined to be 46 and 5.1 ppm, respectively.