A. G. Matveeva

Acetyl-containing phosphine oxides as extractants for actinides and lanthanides

Extraction capability and selectivity of acetyl-containing phosphine oxides R2P(O)CMe2CH2C(O)Me (R = Pr, Bu, n-C5H11, n-C6H13, n-C8H17, Ph) toward actinides (UVI, ThIV) and trivalent lanthanides (LaIII, NdIII, HoIII, YbIII) were studied. The new ligands were shown to be more efficient and selective in the extraction of uranium, thorium, and heavy lanthanides from nitric acid solutions into chloroform as compared to the known extractants such as carbamoylphosphine oxide Ph2P(O)CH2C(O)NBu2, trioctylphosphine oxide (n-C8H17)3P(O), and tributyl phosphate (n-BuO)3P(O).

Re-evaluated data of dissociation constants of alendronic, pamidronic and olpadronic acids

The dissociation constants of (4-amino-1-hydroxybutylidene)bisphosphonic (alendronic) acid, (3-(dimethylamino)-1-hydroxypropylidene)bisphosphonic (olpadronic) acid and (3-amino-1-hydroxypropylidene)bisphosphonic (pamidronic) acid were obtained in aqueous solutions (0.10 M KCl) and micellar solutions of cetylpyridinium chloride (0.10 M CPC) at 25.0°C. With the exception of the third dissociation constant of alendronic acid, the dissociation constants of alendronic, olpadronic and pamidronic acids in aqueous solutions matched literature data. The possibility of sodium alendronate determination by acid-base titration by NaOH solution was theoretically grounded on the basis of re-evaluated data of alendronic acid dissociation constants.

New type of 2-alkyl-substituted 1,8-naphthyridine systems containing a phosphoryl group in the side chain

First organophosphorus derivatives of 2-alkyl-and 2,3-alkylene-substituted 1,8-naphthyridines were synthesized by the Friedländer reaction starting from 2-aminonicotinaldehyde and diphenylphosphoryl(cyclo)alkanones, respectively.

Extraction of f-elements from nitric acid solutions with phosphoryl ketones

The extraction ability and selectivity of a series of phosphoryl ketones Ph2P(O)CH2C(O)Me, and Ph2P(O)CRR’CH2C(O)Me (R = H, Me; R’ = H, Me, n-C5H11, Ph, 2-thienyl, 2-furyl) towards trivalent lanthanides (LaIII, NdIII, HoIII, YbIII) and actinides (UVI, ThIV) were studied. The efficiency and selectivity of the new ligands in the extraction of f-elements from nitric acid solutions into chloroform were compared to those of model phosphine oxide Ph2P(O)Bu and known extractants: tributyl phosphate (BuO)3P(O), trioctylphosphine oxide (C8H17)3P(O), and carbamoylmethyl phosphine oxide Ph2P(O)CH2C(O)NBu2.

Influence of solvent on the strength of cyclic oxygen-containing phosphorus acids

ConclusionsThe dissociation constnats of cyclic oxygen-containing phosphorus acids in absolute alcohol were measured by potentiometric titration in charge transfer circuits.For acyclic phosphorus acids ABPOOH, there is a Brönsted dependence in pK(EtOH)-pk(H2O) coordinates, which does not apply to 1,3-alkylenephosphoric acids, while in the pK(MeNO2)pK(EtOH) coordinates there is a uniform Brönsted dependence for all the acids.

Phosphoryl-containing acidic podands as extractants for recovery of f-elements

The extraction efficiency of uranium(vi), thorium(iv), and lanthanum(iii) from nitric acid solutions to 1,2-dichloroethane was compared for a series of phosphoryl podands of the acidic type different in polyether chain length and number of oxygen atoms: 2-[(HO)(EtO)(O)P]–C6H4–(OCH2CH2)m–OC6H4–2-[P(O)(EtO)(OH)] (1–3, where m = 1–3) and 2-[(HO)(EtO)(O)P]–C6H4–O(CH2)5O–C6H4–2-[P(O)(EtO)(OH)] (4). The synthesis of podands 1 and 4 obtained for the first time is described. The molecular and crystal structures of podand 1 were determined by X-ray diffraction analysis, and the formation of a strong intramolecular hydrogen bond was observed. Podand 2 is the most efficient extractant for the selective recovery of ThIV in the presence of UVI and LaIII among the studied podands. Micellar aggregates 3–5, 6–90, 3–70, and 7–10 nm in size were found by the dynamic light scattering data in thorium extracts of podands 1–4, respectively.

β-Diphenylphosphorylated alkanones and related compounds: synthesis and structure

The reactions of diphenyl(diisopropyl)chlorophosphine with arylidene(heteroarylidene)-acetones and 3-benzylidenepentane-2,4-dione in the presence of acetic acid proceed at a high rate at room temperature to afford the corresponding β-diorganylphosphorylated alkanones and alkanediones in high yields. The reaction of diphenylchlorophosphine with 4-methoxybut-3-en-2-one and dibenzylideneacetone carried out under similar conditions at the equimolar reagent ratio can serve as a convenient method for the synthesis of unique β-diphenylphosphorylalkenones. The structures of compounds obtained were established by IR, Raman, and NMR spectroscopy and X-ray diffraction.

Complexes of (2-methyl-4-oxopent-2-yl)diphenylphosphine oxide with uranyl and neodymium nitrates: synthesis and structures in the solid state and in solution

The reactions of (2-methyl-4-oxopent-2-yl)diphenylphosphine oxide (L) with uranyl and neodymium nitrates afforded complexes with compositions M: L = 1: 2 and 1: 3. These complexes were characterized by X-ray diffraction, IR spectroscopy, and elemental analysis. In the solid complexes, phosphine oxide L has a variable denticity. Studies by 1H and 31P NMR and IR spectroscopy showed that in chloroform, the mononuclear complexes [UO2(O-L)2-(O,O-NO3)2], [Nd(O-L)2(O,O-NO3)3] and [Nd(O-L)3(O,O-NO3)3] are neutral, and the ligand molecules are coordinated to the metal cation through the phosphoryl oxygen atom.

N-Substituted 2-aminoethylidenediphosphonic acids as complexones

A novel complexone, 2-dimethylaminoethylidenediphosphonic acid, was synthesized. Its acid-base and complexation properties were studied by potentiometric titration in aqueous solutions (25 °C) and compared to those of 2-amino-1-hydroxyethylidenediphosphonic acid and ω-aminoalkylidenediphosphonic analogs. Parameters of efficiency and selectivity of complexation were determined. The influence of the alkylidene chain length on complexone properties in a series of ω-aminoalkylidenediphosphonic acids was analyzed.

Multi-Gaussian Monte Carlo Analysis of PELDOR Data in the Frequency Domain

Abstract Pulsed double electron–electron resonance technique (PELDOR or DEER) is often applied to study conformations and aggregation of spin-labelled macromolecules. Because of the ill-posed nature of the integral equation determining the distance distribution function, a regularization procedure is required to restrict the smoothness of the solution. In this work, we performed PELDOR measurements for new flexible nitroxide biradicals based on trolox, which is the synthetic analogue of α-tocopherol; spin-labelled trolox derivatives are investigated as potential anti-cancer drugs. We use regularization by an approximation of the solution with a sum of limited number of Gaussians, by varying their positions, widths and amplitudes. Their best-fitted values were found by a completely random Monte Carlo process. The use of the frequency-domain PELDOR data allowed diminution of the artifacts induced by spin–spin electron–nuclear and intermolecular electron–electron interactions. It was found that for the all biradicals studied, the use of three Gaussians was enough for good agreement with the experiments. The number of trials for obtaining satisfactory result was found to be quite reasonable, which is explained by presence of the singularity in the core of integral equation. The maxima of inter-spin distance distribution for different biradicals were found to vary between 1.5 and 2.3 nm, depending on the linkers between the Trolox core and nitroxides. The distance distributions around these positions reflect flexibility of the biradicals.