O,O′-dialkyl(5-ethyl-2-hydroxyphenyl)phosphonates (HL) in combination with the synergistic additive, trioctylphosphine oxide (TOPO), were considered as lithium-selective extractants for the first time. The possibility of these compounds to exhibit lithium-selective properties in the extraction of alkali metals (Li, Na, K) was predicted by quantum chemical calculations, the results of which were confirmed by extraction experiments. It is shown that the composition of the extracted species can vary depending on the extraction conditions. At the same time, O,O′-dialkyl(5-ethyl-2-hydroxyphenyl)phosphonates can participate in extraction both as cation-exchange extractants and as neutral extractants, competing with TOPO.

The effect of the ionic liquid, 1-butyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide, on the extraction of lanthanides(III) from nitric acid solutions with phosphoryl-containing podands (2-(2-diphenylphosphoryl)-4-ethylphenoxy)methyl)diphenylphosphine oxide (1), (2-(2-diphenylphosphoryl)-4-ethylphenoxy)ethyl)diphenylphosphine oxide (2), and 2-[2-(diphenylphosphoryl)-4-ethylphenoxy]-N,N-dioctylacetamide (3) was studied. The stoichiometry of the extracted complexes was determined. The efficiency of extraction of lanthanides(III) with solutions of compounds 1–3 in dichloroethane from nitric acid solutions increases in the order 3 < 2 < 1. It has been established that, when replacing dichloroethane with an ionic liquid as a diluent, the extraction efficiency enhances. The magnitude of this effect decreases in the series of compounds 3 > 2 > 1. In the case of compound 1, the replacement of dichloroethane with an ionic liquid as a solvent is accompanied by a decrease in the extraction of lanthanides(III) at [HNO3] > 1.5 M.

In this work, for the first time we proposed a mixture based on 2-nitro-4-nonylphenol as a lithium-selective binary extractant, in which the nitro group simultaneously participates in the formation of a six-membered metallocycle and increases the acidity of the phenolic group. The extraction of alkali metals (Li, Na, K) by a mixture of 2-nitro-4-nonylphenol and trioctylphosphinoxide in dodecane was studied in detail. The extraction of Li from mother liquors after Li2CO3 precipitation was considered as a practical application of the new binary extractant. It was shown that by using only liquid extraction methods, a high degree of concentration and purification of final product can be achieved. Mother liquor of Li2CO3 precipitation was concentrated by Li more than 50 times. Degree of lithium concentrate purification from Na and K was more than 5500 and 100,000 times, correspondingly.

Extraction of U(VI), Th(IV), REE(III), and Sc(III) from nitrate and perchlorate solutions with solutions of phosphorylpodand 1,5-bis[di( p -tolyl)phosphoryl]-3-oxapentane (L) in 1,2-dichloroethane depending on the concentration of acids in the aqueous phase was studied. The stoichiometry of the extractable complexes was determined. The magnitude of the “perchlorate” effect was shown to diminish upon an increase in the acid concentration, and REE(III) ions, to be extracted by podand L from HClO 4 solutions less efficiently than from HNO 3 solutions at acid concentrations above 0.3 M. During the extraction of Sc(III) the “perchlorate” effect also manifests itself in the region of high acid concentration, which leads to an increase in the separation factors of Sc(III) and REE(III), U(VI), and Th(IV) during extraction with podand L from HClO 4 solutions.

In order to study the physicochemical and biological properties of the coordination compounds of bioactive metal ions with 2-hydroxyphenylphosphonic acid derivatives, the reactions of 2-hydroxy-5-ethylphenylphosphonic acid (Н3L1) with copper(II) perchlorate, sulfate, nitrate, and acetate in water was studied for the first time. It has been found that, regardless of the ratio of reagents, in the case of copper(II) perchlorate, sulfate, and nitrate, a complex of the composition [Cu(H2L1)2(Н2О)2] is formed in high yields, whereas in the case copper(II) acetate a complex [Cu(HL1)(H2O)2] is formed, the composition of which was determined by elemental analysis and IR and electronic spectroscopy. The quantum-chemical calculations for the [Cu(H2L1)2(Н2О)2] and [Cu(HL1)(H2O)2] complexes by the density functional theory (DFT) method were carried out for the first time. The cytotoxic properties of the Н3L1 acid and the [Cu(HL1)(H2O)2] and [Cu(H2L1)2(Н2О)2] complexes with respect to HeLa tumor cells of human cervical adenocarcinoma were studied. The accumulation of the above complexes in HeLa cells was proved by laser confocal microscopy.

A complex of zinc(II) with 2-hydroxy-5-ethylphenylphosphonic acid (H 3 L) of the composition [Zn(H 2 L) 2 (Н 2 О) 2 ][Zn(HL)(Н 2 О)]·H 2 O ( I ) was synthesized, the structure of which was established based on data of X-ray diffraction and elemental analysis, quantum chemical calculations, as well as IR and electron absorption spectroscopies. The stability constants of H 3 L acid complexes with zinc(II) perchlorate in water were determined by potentiometric titration. The cytotoxic properties of H 3 L acid and complex I were studied for the first time on HeLa cells (human cervical adenocarcinoma). The results on the accumulation of complex I in HeLa cells were obtained by laser confocal microscopy.

Russia enjoys large reserves of lithium, enabling it to fully meet the needs of the domestic market with the prospect of developing production of lithium-ion batteries, electric vehicles, unmanned systems, and portable electronics. Lithium mining is a complex process determined by the climate, the composition of the brine, and the effectiveness of available technologies. Today, Russian lithium extraction technologies are developing in two directions: sorption and extraction. The article, which is based on the materials of the report delivered at the meeting of the Presidium of the Russian Academy of Sciences on April 11, 2023, discusses general trends and prospects for improving lithium extraction methods, including liquid–liquid extraction and sorption.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

The effect of the ionic liquid {trioctylammonium bis[(trifluoromethyl)sulfonyl]imide} on the extraction of REE(III) with tetraoctyldiglycolamide from nitric acid solutions has been studied. It has been found that efficiency and selectivity of the metal ions extraction from nitric acid solutions are significantly increased in the presence of the ionic liquid in the organic phase. The influence of the aqueous phase acidity on the change in the distribution ratios of REE(III) has been considered, and stoichiometry of the extracted complexes has been elucidated.

Extraction of microquantites of U(VI), Th(IV), and REE(III) from nitric acid solutions with solutions of (o-phenyleneoxymethylene)diphosphine dioxides with phenyl and butyl substituents at the phosphorus atom in the OCH2P(O)R-2 fragment was studied. The stoichiometry of the extracted complexes was determined. The influence of the extractant structure, the concentration of HNO3 in the aqueous phase, and the nature of the organic solvent on the extraction efficiency of REE(III), U(VI), and Th(IV) into the organic phase is considered. The presented data showed that the phosphoryl groups in the (o-phenyleneoxymethylene)diphosphine dioxide molecule are not equivalent. In contrast to the noticeable decrease in the efficiency of REE(III) extraction from nitric acid solutions when phenyl radicals are replaced by butyl radicals in the phosphoryl group P(O)R-2 directly attached to the phenylene ring, the replacement of the OCH2P(O)Ph-2 fragment in the dioxide molecule by OCH2P(O)Bu-2 only slightly reduces the REE(III) distribution factors in such media. At the same time, the extraction efficiency of U(VI) and Th(IV) from nitric acid solutions increases with this replacement.

Федеральное государственное бюджетное учреждение наукиИнститут неорганической химии им.А. В. Николаева Сибирского отделения Российской академии наук

Carbon dots (CDs) have been widely applied in metal ion recognition and detection, which makes them promising in the fields of environmental monitoring and biomedical science. However, CDs usually contain multiple functional groups that have different affinities for metal ions, so the relationship between CDs and recognized metal ions is ambiguous, which limits the prediction of recognized metal ions. Herein, CDs with different chelating ligands were target synthesized via free radical polymerization in combination of hydrothermal carbonization technology, the precursors directional converted into CDs. The tailor-made CDs with ethylenediamine tetraacetic acid (EDTA, EfCDs) and hydroxyethylidene diphosphonic acid (HEDP, HfCDs) chelating ligands were synthesized with high synthetic yields of 86.7% and 72.5%, respectively. The coordination constant (K) and the number of chelation site (n) of EfCDs for Fe3+ were (3.92 +/- 0.03) x 10(4) M-1 and 3.62 +/- 0.18, while the values of K and n of HfCDs for Cu2+ were (5.95 +/- 0.04) x 10(5) M-1 and 1. EfCDs and HfCDs can serve as fluorescence probes for specific recognition of Fe3+ and Cu2+, respectively. Based on the metal-chelating affinity of EDTA and HEDP for Fe3+ and Cu2+ (lgK(EDTA-Fe) = 25.1, lgK(HEDP)-Cu = 12.5), EfCDs and HfCDs were predicted to specifically recognize Fe3+ and Cu2+. We established the exponential type functions between fluorescence quenching degree (1-F/F-0) and coordination constant (lgK) of EDTA or HEDP to facilitate the prediction of specific recognition of metal ions. This study proposes a new strategy for heavy metal ions specific recognition using CDs with tailor-made chelating ligands.

1,3,5-Tris(2-diphenylphosphoryl-4-ethylphenoxymethyl)benzene (L′), a phosphorylcontaining tripodand, was synthesized for the first time in order to find extraction systems for efficient recovery of lanthanides. The main regularities of extraction of lanthanide(III) ions with mixtures of L′ and 4-benzoyl-5-methyl-2-phenyl-3-pyrazolone (HL) into CHCl3, 1,2-dichloroethane, toluene, and carbon tetrachloride from chloride solutions were elucidated. A significant synergistic effect, associated with the formation of hydrophobic mixed-ligand complexes of lanthanides(III), was found. The stoichiometry of the extracted complexes was determined by the equilibrium shift method. The equilibrium constants and values of the synergistic effect in the LnIII—L′—HL—dichloroethane system were calculated. The influence of the nature of the organic solvent and the composition of the aqueous phase on the efficiency of lanthanide(III) ion extraction into the organic phase was considered.

The copper(ii) complex [Cu(H2L1)(2)(H2O)(2)] with (2-hydroxyphenyl)phosphonic acid (H3L1) was synthesized. The composition and structure of the complex were determined by X-ray diffraction, elemental analysis, and IR spectroscopy. Quantum chemical calculations of the structure of the H3L1 molecule were performed by the density functional theory (DFT). The protonation constants of H3L1 and the stability constants of its complexes with Cu2+ in water were determined by potentiometric titration. The cytotoxic properties and the accumulation of the [Cu(H2L1)(2)(H2O)(2)] complex in human cervical adenocarcinoma HeLa cells were evaluated for the first time, thereby demonstrating that this complex is promising for further biological studies.

The extraction of U(VI), Th(IV), Am(III), and lanthanide(III) ions and HNO3 from nitric acid solutions with 1,2-dichloroethane solutions of 3-oxapentane-1,5-diylbis(diphenylphosphine)dioxide and its structural analogues was studied. The stoichiometry of the extractable complexes was determined. The effects of the extractant structure and HNO3 concentration in the aqueous phase on the efficiency of the metal ions extraction into the organic phase were considered. The successive replacement of two methylene groups connecting the ether oxygen atom with Ph2P(O) groups in the podand molecule by o-phenylene groups leads to an increase in the efficiency of Th(IV) Am(III), and Ln(III) extraction from nitric acid solutions, but has little effect on the efficiency of U(VI) extraction.

The structures of complexes [CdL1(NCS)2(H2O)2] (I), [Cd(L1)2(H2O)2][CdI4]⋅0.5H2O (II), where L1 is 1,8-bis[(diphenylphosphoryl)methoxy]-3,6-dioxaoctane, and [Cd(μ-L2)I2]n (III), where L2 is 1,3-bis[oxymethyl(diphenylphosphoryl)]propane have been determined by single-crystal X-ray diffraction. The structures of I and II are the first examples of mononuclear cadmium complexes with phosphoryl podand. The structure of III is formed by 1D chains. The synthesis of 2,6-bis[2-(diphenylphosphoryl)-4-ethylphenoxymethyl]pyridine (L3) is described. The stability constants of complexes of cadmium nitrate with podands L2 and L3 have been determined by spectrophotometric titration in acetonitrile. It has been found that ligand L3 forms in solution not only a 1 : 1 (M : L) complex (log β1 = 4.92 ± 0.11) but also a 2 : 1 binuclear complex (log β2 = 9.42 ± 0.11), which results in binding of 85.1

A comparative study of samarium-153 complexation with several phosphonate ligands (acyclic and cyclen-based) was carried out. Methods of quality control of the resulting complexes were proposed, and their biological behavior was determined. It is noted that the biological behavior of the radionuclide compound is the principal criterion for choosing it as an active pharmaceutical substance for the development of radiopharmaceuticals.

Novel solvent-impregnated resins (SIRs) were prepared by treatment of styrene–divinylbenzene copolymer (LPS-500) with mixtures of the promising polydentante extractant (2-diphenylphosphoryl)-4-ethylphenoxy)methyl)diphenylphosphine oxide (L) and an ionic liquid [C4mim]+[Tf2N]−for the extraction chromatography recovery of Nd(III) from nitric acid solutions. It was shown that introduction of the ionic liquid into the SIR composition results in considerable enhancement of the Nd(III) recovery efficiency compared with resin impregnated only by L in slightly acidic media. The influence of the L: ionic liquid molar ratio in the SIRs composition, their percentages, concentration of metal and HNO3 in the eluent, and acid type on the value of synergistic effect and adsorption efficiency of Nd(III) recovery was studied. The SIR containing 40% of mixture of L and [C4mim]+[Tf2N]− with molar ratio 2:1 turned out to be the most efficient. The selectivity of Nd(III) separation from light and heavy rare-earth elements was studied and the optimal conditions of Nd(III) adsorption recovery and stripping by this SIR were chosen. It was found that in recovery efficiency of Nd(III) developed SIR exceeded the SIR containing Cyanex 923 (a mixture of monodentate trialkylphosphine oxides) and [C4mim]+[Tf2N]−.

The removal of actinides and rare earth elements (REEs) in nitric acid solutions; produced in nuclear processes; is a challenging job. The present article describes the sorption behavior of oxidized multilayer graphene (o-MG) to actinides and rare earth elements (REEs) in nitric acid solutions (up to 3 mol L-1 HNO3), including nitrogen and phosphorus-containing reagents. The conditions for obtaining new sorption materials in a compact form; by adding directly a reagent (organic ligand) and a suspension of o-MG to nitric acid solutions; were optimized. o-MG was modified by using tetraoctyldiglycolamide, diphenyl-dibutylcarbamoyl-methyl-phosphine oxide, tri-octyl-phosphinoxide, di-(2-ethylhexyl) phosphoric acid, tributyl phosphate and di-2-ethyl-hexyl-methyl-phosphonate reagents were used. The formation time of the solid-phase extractants compact phase was 20-240 min. The new materials sorption capacity to U (VI), Th (IV), Pu (IV), La (III), Ce (III) and Eu (III) in nitric acid solutions (3 mol L-1 HNO3) was determined. The elements distribution coefficients were K-d similar to 10(3)-10(4) mL g(-1). The efficiency of the obtained materials was confirmed by the data on the solid-phase isolation and separation of actinides and REEs from nitric acid solutions (3 mol L-1 HNO3) in the presence of macro components (Cs, Sr, Fe, Mo, Pd, Zr, Co), which can be formed during recycling processes of spent nuclear materials and components used in nuclear medicine. (C) 2021 Elsevier B.V. All rights reserved.

Complex [Cu(H2L)2(Н2О)2] has been obtained by the reaction of copper(II) with 2-hydroxy-5-ethylphenylphosphonic acid (H3L), and its structure was studied by X-ray diffraction. Protonation constants of acid H3L and stability constants of its complexes with Cu2+ in water have been determined by potentiometric titration. Complex [Cu(H2L)2(Н2О)2] has been found to show low toxicity and high analgesic activity.