A. M. Safiulina

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).

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.

Linear models of three-phase extraction processes

Single-stage and multistage linear-law three-phase extraction processes are considered, and analytical relationships for calculating the extraction efficiency are derived.

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.

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.

Extraction of lanthanides(III) by phosphorylated naphthyridine ligands from carbonate solutions

The extraction capacities and selectivities of 1,8-naphthyridine-based neutral organophosphorus reagents in extracting trivalent lanthanides (Ln, Nd, Ho, Yb) from carbonate solutions were studied. The length and nature of the linker between the naphthyridine and phosphoryl moieties were found to have considerable influence on the efficiency and selectivity of lanthanide extraction.

N-(1,5-dimethyl-3-oxo-2-phenyl-1,2-dihydropyrazol-4-yl)-P,P-diphenylamidophosphinate and its complexes with neodymium(III), erbium(III), thorium(IV), and uranyl nitrates: Synthesis and crystal and molecular structure

A new phosphoryl-containing ligand based on 4-aminoantipyrine-N-(1,5-dimethyl-3-oxo-2-phenyl-1,2-dihydropyrazol-4-yl)-P,P-diphenylamidophosphinate (L) was synthesized. In crystals, the L molecules were found to be combined in centrosymmetric dimers through N-H…O=C hydrogen bonds. The complexes of L with neodymium(III), erbium(III), thorium(IV), and uranyl nitrates were obtained, and their structures were determined. The bands of the C=O and P=O groups in the IR spectra of these complexes are shifted toward low frequencies (by 50–65 and 40–70 cm−1, respectively), which is indicative of a bidentate coordination of the organophosphorus ligand. According to the X-ray crystallography data, uranyl is bidentately coordinated by both the L molecule (through the C=O and P=O groups) and two nitrate anions.

Effect of the nature of substituents at the phosphorus atom on extraction properties of phosphorylketones toward f-elements

Extraction abilities of phosphorylketones with alkyl and cycloalkyl substituents at the phosphorus atom R2P(O)CH2CH2C(O)Me (R = Pri, But) and R2P(O)CHPhCH2C(O)Me (R = Pri, cyclo-C6H11) toward UVI, ThIV, and a series of tervalent lanthanides (LaIII, NdIII, HoIII, YbIII) were studied. The efficiencies and selectivities of recovery of f-elements from nitric acid solutions to chloroform by these ligands were compared with extraction properties of both the model phosphorylketones with phenyl substituents at the phosphorus atom Ph2P(O)CH2CH2C(O)Me and Ph2P(O)CHPhCH2C(O)Me and other known extractants such as tributyl phosphate (BuO)3P(O), trioctylphosphine oxide (C8H17)3P(O), and carbamoylphosphine oxide Ph2P(O)CH2C(O)NBu2.

α- and β-diphenylphosphorylated secondary alkanols: I. general method of synthesis and extraction properties towards f-elements

A simple and effective general method of synthesis of α- and β-diphenylphosphorylated secondary alkanols by the reduction of the corresponding phosphorylalkanones with NaBH4 was developed. The extraction properties of the resulting phosphorylalkanols Ph2P(O)(CR2)nCH2CH(OH)Me (n = 0, 1; R = H, Me) were studied in the recovery of f-elements (LaIII, NdIII, HoIII, YbIII, UVI, ThIV) from nitric acid solutions into chloroform and compared with those of both related phosphorylketones and known extractants (n-BuO)3PO, (n-C8H17)3PO, and Ph2P(O)CH2C(O)N(n-Bu)2.

Recovery of lanthanides from digested phosphogypsum solutions using a new organophosphorus extractant, 5-(diphenylphosphoryl)hexan-3-one

Extraction of rare earth elements from digested phosphogypsum solutions with a number of well-known organophosphorus compounds, tributyl phosphate, trioctylphosphine oxide, and bis(2-ethylhexyl)-phosphoric acid, as well as with phosphoryl ketone Ph2P(O)CHMeCH2C(O)Et, was studied. It was found that this phosphoryl ketone is the most effective reagent for obtaining the mixed lanthanide concentrate. An improved synthetic route to this compound was developed.