A. R. Garifzyanov

Synthesis of new liophilic functionalized aminomethylphosphine oxides and their acid-base and membrane-transport properties toward acidic substrates

A large number of new lipophilic mono- and bisphosphinylamines including those possessing additional potential centers of coordination was synthesized on the basis of the Kabachnik-Fields reaction, and acid-base and membrane transport properties of the synthesized compounds toward the mono- and polybasic carboxylic acids were studied. By their basicity all the synthesized aminophosphine oxides were shown to be inferior to their aliphatic amine precursors. Introduction of the second phosphinyl group so strongly decreases the basicity that the determination of pKa by potentiometric method becomes impossible. Interrelation between the structure of aminophosphinyl carrier and substrate and the efficiency of the membrane transport of acidic substrates are discussd.

Extraction of scandium ions by new aminophosphinyl extractants

Extraction of Sc(III) ions by new aminophosphinyl compounds containing one or two methylenediorganylphosphinyl groups at the nitrogen atom was studied with a target of the development of effective and selective extractants of trace elements. The selection of extractants was due to their high hydrolytic stability in the acid media, commonly used at the extraction of metal ions in the industrial hydrometallurgical processes. The study of extraction of hydrogen chloride and nitric acids with the selected aminophosphinyl compounds allowed a discovery of substances with the low basicity, which were characterized by the low coefficient of the acids extraction. Highly effective extractants of Sc(III) were found possessing high coefficients of extraction and high degree of selectivity in the separation of Sc(III) ion from the ions of satellite metals.

Liquid extraction of some rare earth elements with aminomethylphosphine oxides

Methods were developed of the solvent extraction from aqueous solutions of hydrochloric, nitric, and perchloric acids of the triply charged ions of rare earth elements including samarium, lutetium, dysprosium, neodymium, and ytterbium, using as reagents the lipophilic aminomethylphosphine oxides containing two or four dialkylphosphinyl groups, and toluene, chloroform, and methylene chloride as the organic media. The study of the effect of concentration of mineral acids on the degree of metal extraction showed that the highest extraction efficiency of lanthanides is achieved with bis(dihexylphosphinylmethyl)octylamine (I) from perchloric media: extraction degree 80%, whereas extraction from the solutions in two other acids did not exceed 30%. It was shown that the highest selectivity was reached at the extraction of scandium in all the extraction systems. A possible mechanism of extraction is discussed.

Synthesis and acid-base properties of aminophosphine oxides on the basis of natural amino acids

In recent years aminophosphonate derivatives of the natural amino acids attracted a considerable interest because of their pronounced physiological activity and specific complexing properties [1, 2]. However, the phosphine oxide derivatives of amino acids, which can show high efficiency in liquid and membrane extraction processes [3], were not described up to day. Using the Kabachnik–Fields reaction [1] in a dioctylphosphine–formaldehyde–amino acid threecomponent system, we synthesized a series of αaminomethylphosphine oxides containing structural fragments of glycine (I), β-alanine (II), and its N-butyl derivative (III) of the general formula Oct2P(O)· CH2NR(CH2)nC(O)OH, R = Oct2P(O)CH2, n = 1 (I); R = Oct2P(O)CH2, n = 2 (II); R = C4H9, n = 2 (III).

Synthesis, transport and ionophore properties of α,ω-biphosphorylated azapodands: V. Acid-base properties of new phosphorylated azapodands and α,ω-diamines and their participation in the membrane transport of I–III groups metal ions

Acid-base properties of newly and previously synthesized phosphorylated azapodands and α,ω-diamines and their amine precursors were studied. We found that they differ in the same range as has been found previously for the other aminophosphoryl compounds. The investigation of the processes of passive membrane ion transport of a series of metals of I–III groups by these reactants showed with all diphosphoryl diamines higher values of the transfer flow of the ions Sc(III), Nd(III), and Sm(III), than the ions of alkali and alkaline earth metals. Under the conditions of active membrane transport the azapodand IV exhibits high efficiency in the ion transport of Sr(II) and Ba(II), while diphosphoryldiamine III exhibits effective transport of Nd(III) ions. The factors that determine the efficiency and selectivity of the membrane extraction of the I–III groups metal ions by these diphosphoryl diamines are discussed.

α-Amino acetals containing a phosphonate or phosphine oxide group. Synthesis and reactions with resorcinols

New α-amino acetals containing a phosphonate or phosphine oxide group were synthesized by the Kabachnik-Fields reaction in the ternary system amino acetal-paraformaldehyde-dialkyl phosphonate (or dialkylphosphine oxide). Condensation of dialkyl (2,2-dimethoxyethylamino)methylphosphonates with resorcinol and its derivatives in ethanol in the presence of hydrochloric acid, apart from the corresponding 2,2-bis(polyhydroxyphenyl) ethylammonium salts, gave 2,5-bis(polyhydroxyphenyl)-1,4-bis[(dialkoxyphosphoryl)methyl]-piperazines. Dialkyl[(2,2-dimethoxyethylamino)methyl]phosphine oxides (Alk = C8H17, C10H21) did not react with resorcinol derivatives under similar conditions, and analogous ammonium salts were obtained by heating the reactants in boiling trifluoroacetic acid.

Membrane transport of metal ions with lipophilic aminomethylphosphine oxides

The processes of membrane transport of ions of scandium(III), samarium(III), gadolinium(III), neodymium(III), aluminum(III), and a number of alkali and alkaline earth metals through liquid membrane impregnated with aminophosphoryl carriers of different structures were studied. Selectivity of bis (dialkylphosphinyl)amines towards scandium was found to be significantly higher than the selectivity of diphosphinylpiperazine and monophosphinylamine in particular. The dependence of transfer efficiency on the concentration of substrates and carriers was revealed. Optimal conditions for transporting rare and trace metal ions through the membrane were found, and the mechanism of transmembrane transport was discussed.

β- and γ-amino acetals containing phosphine oxide groups. Synthesis and reactions with resorcinol derivatives

New β- and γ-amino acetals containing phosphine oxide groups were synthesized by the Kabachnik-Fields reaction of β- and γ-amino acetals with paraformaldehyde and dialkylphosphine oxides. Heating of the resulting β- and γ-amino acetals with 2-methylresorcinol and pyrogallol in boiling trifluoroacetic acid afforded (dialkylphosphoryl)(ω,ω-diarylalkyl)ammonium trifluoromethanesulfonates.

Sinergetic membrane extraction of lithium ions with new organophosphorus carriers

We have studied membrane transport properties towards alkali metal ions of sinergetic mixtures of organophosphorus carries, N,N-bis(dihexylphosphorylmethyl)octylamine and didecylthiophosphorus or didecyldithiophosphorus acids. The influence of main parameters of extraction (pH of the feed phase as well as concentration and ratio of the carriers in the membrane) on the membrane transport rate and selectivity with respect to lithium has been analyzed. Conditions of efficient and selective (to separate K+ and Na+) membrane extraction of Li+ have been established. Advantages of the studied systems in comparison with some previously known ones are demonstrated.

Membrane extraction of metal ions by aminophosphoryl reagents in the active transport conditions

The process of membrane extraction of rare earth ions, Nd(III), Sc(III), and Sm(III), and also the accompanying them in the natural raw material ions Al(III) and Mg(II), by N,N-bis(dihexylphosphorylmethyl)octylamine (BPA) was investigated under the conditions of active membrane transport, and its high efficiency and selectivity was demonstrated with respect to the two first rare earth metals. The influence of principal parameters of the three-phase extraction process, including the nitrate ion concentration, the releasing aqueous phase acidity, the extracting agent concentration in the membrane, and the nature of the membrane solvent, on the membrane permeability, characterizing the efficiency and selectivity of membrane transporters, was established. Comparison of the membrane permeability in the process of transmembrane transport of Nd(III) and Sc(III) with BPA and monophosphorylated amines showed a significant advantage of the biphosphorylated amine extractant.