R. R. Davletshin

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.

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, 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.

Synthesis, transport, and ionophore properties of α,ω-biphosphorylated azapodands: VII. Membrane transport of mineral acids by phosphorylated α,ω-diamines and azapodands

Phosphorylated α,ω-diamines and azapodands were shown to be effective agents in the processes of liquid and membrane extraction of substrates of different nature, including the ions of alkali and alkaline earth, rare and trace metals, and monoand polyhydric carboxylic acids [1-3]. It is known that extraction of metals from mining of raw materials is performed usually by transferring them into the aqueous phase in the form of salts of strong mineral acids, mostly nitric, hydrochloric, perchloric, sulfuric, and other acids. Therefore, information on the processes of extraction of inorganic acids by biphosphoryldiamide carriers is necessary rather than important: the optimization of metal extraction is not possible without this knowledge.

Synthesis, transport, and ionophoric properties of α,ω-biphosphorylated azapodands: VI. New cesium-selective electrodes based on the phosphorylated azapodands

New cesium-selective electrodes containing as an electrode active substance biphosphorylated azapodands: 1,8-bis(dioctylphosphorylmethylamino)-3,6-dioxaoctane (I), 1,10-bis(dioctylphosphorylmethylamino)-4,7-dioxadecane (II), and 1-(dioctylphosphorylmethylamino)-10-[(dioctylphosphorylmethyl)benzylamino]-4,7-dioxadecane (III) were developed, and the composition of the membranes of these electrodes was optimized. The high selectivity of electrodes based on the ionophores I–III toward Cs(I) ion, which can be determined on the background of the majority of the other ions of alkali and alkaline earth metals, including the close to it by size Rb(I) ion, was established.

Synthesis of the azapodands with phosphoryl terminal groups

GRAPHICAL ABSTRACT ABSTRACT New lipophilic phosphorylated azapodands with different substituents at the nitrogen atom were synthesized via the Kabachnik–Fields reaction in the three-component system: di-p-tolylphosphinous acid–formaldehyde–1,8-diamino-3,6-dioxaoctane. The reaction was carried out in toluene or acetonitrile media, with p-toluenesulfonic acid acting as a catalyst.

Membrane extraction of alkaline earth metal by phosphorylated azapodands

ABSTRACT Membrane transport properties of the new lipophilic phosphorylated azapodands toward Сa(II), Ва (II), Mg(II), and Sr(II) were studied. The investigation of the processes of passive membrane ion transport showed the high values of the transfer flow of the alkaline earth metals’ ions with all carriers. It was found that N,N’-bis(di-p-tolylphosphorylmethyl)-1,8-diamino-3,6-dioxaoctane (I) is the most effective carrier among all compounds studied. GRAPHICAL ABSTRACT

Synthesis and structure of aminomethylphosphabetaines

It is known that some dialkyl aminoalkylphosphonates in solution spontaneously undergo intramolecular O→N migration of alkyl group with formation of zwitterionic alkyl ammonioalkylphosphonates which may be regarded as synthetic analogs of phosphonoand phospholipids capable of acting as monoand multidentate ligands in donor–acceptor complexes with some Lewis acids [1]. While searching for efficient and selective liquid and membrane extractants for various substrates, we have developed a new convenient procedure for the synthesis of phosphabetaines. This procedure implies N-alkylation of potassium alkyl aminomethylphosphonates prepared by hydrolysis of the corresponding dialkyl aminomethylphosphonates with aqueous sodium hydroxide. Alkyl hydrogen aminomethylphosphonates (RO)(OH)P(O)CH2NR′R′ were synthesized in almost quantitative yield (according to the P NMR data) by the Kabachnik–Fields reaction [2] and were converted without isolation and special purification into potassium salts I–III. The latter were purified by treatment with ethyl acetate; nonpolar organic impurities were thus removed, whereas salts I–III did not dissolve. If this procedure was inefficient, the salts were dissolved in methanol, and small amount of dilute hydrochloric acid was added to the solution. Solid impurities were filtered off, and the alkyl hydrogen phosphonate was converted again into potassium salt by adding an equimolar amount of 50% aqueous potassium hydroxide. Quaternization of potassium salts with benzyl chloride gave zwitterionic ammoniomethylphosphonates IV–VI as well shaped crystals, which can be readily purified by recrystallization from methanol or ethyl acetate. The structure of IV–VI was determined on the basis of their IR and H and P NMR spectra, and the structure of ethyl [benzyl(dipropyl)ammoniomethyl]phosphonate (IV) was proved by the X-ray diffraction data. More detailed information on the structure and properties of new phosphabetaines will be reported elsewhere. The synthesis of dialkyl aminomethylphosphonates was described in [2]. Potassium ethyl [(dipropylamino)methyl]phosphonate (I). Yield 75%, mp 188°C. IR spectrum (mineral oil), ν, cm: 1104 (P=O), 1061 (P–O–C). H NMR spectrum (CDCl3, 300 MHz), δ, ppm: 0.86 t (3H, CH3CH2, JHH = 7.28 Hz), 1.23 t (6H, CH3, JHH = 7.04 Hz), 1.39–1.52 m (4H, NCH2CH2), 2.52–2.65 d.d (2H, PCH2) and t (4H, NCH2); 3.86–3.95 m (OCH2). P NMR spectrum (dioxane, 122.4 MHz): δP 20.4 ppm. Potassium butyl [(dibutylamino)methyl]phosphonate (II). Yield 78%, mp 205°C. IR spectrum (mineral oil), ν, cm: 1194 (P=O), 1061 (P–O–C). H NMR spectrum (CDCl3, 300 MHz), δ, ppm: 0.95 t (9H, CH3, JHH = 7.24 Hz), 1.23–1.67 m (12H, CH2), 2.57–2.74 t (NCH2), 2.69 d (2H, PCH2, JPH = 12.80 Hz), 3.81–3.91 m (2H, OCH2). P NMR spectrum (dioxane, 122.4 MHz): δP 21.3 ppm. Potassium 3-methylbutyl [(dibutylamino)methyl]phosphonate (III). Yield 80%, mp 198°C. IR specI, IV, R = Et, R′ = Pr; II, V, R = R′ = Bu; III, VI, R = iso-C5H11, R′ = Bu. ISSN 1070-4280, Russian Journal of Organic Chemistry, 2013, Vol. 49, No. 4, pp. 625–626.

Synthesis, transport, and ionophore properties of α,ω-bisphosphorylated azapodands: IX. Extraction of metal ions with quasiliquid emulsions on the basis of N,N′-bis(dioctylphosphorylmethyl)-1,8-diamino-3,6-dioxaoctane and acidic components

Processes of extraction of ions of the I–IV group metals from acidic water solutions with paraffin quasiliquid emulsions containing neutral phosphorylazapodand, bis(dioctylphosphorylmethyl)-1,8-diamino-3,6-dioxaoctane I, and acidic components, bispentadecylphosphoric II and hexadecylsulfonic acid III is studied. High effectiveness of extraction of metal ions with these extraction compositions is established. It significantly exceeds the effectiveness of liquid extraction in the same systems, especially of ions of the II group metals. The extraction of three-charged ions proceeds more effectively by the mixture of organophosphorus reagents I and II, than with the composition consisting of azapodand I and organosulfur acid III.

Acid-base properties of α-aminomethylphosphine oxides

Ionization constants of a series of aminomethylphosphine oxides and respective amino precursors, as well as their isostructural amino phosphonates in water-2-propanol or water medium were determined. The main regularities of the effect of the phosphoryl group on the protolytic equilibria involving mono- and bisphosphorylated amines and diamines were found. The environment effect on the ionization constants of hydrophilic aminophosphoryl compounds and amines was estimated quantitatively. The relationship between the dissociation constants of aminophosphoryl compounds and related constants of amino precursors in the framework of the principle of linearity of free energies was demonstrated.