Search results for "Phosphinate"
showing 10 items of 21 documents
α-Aminophosphonates, Phosphinates, and Phosphine Oxides as Extraction and Precipitation Agents for Rare Earth Metals, Thorium, and Uranium : A Review
2022
α-Aminophosphonates, -phosphinates, and -phosphine oxides are a group of organophosphorus compounds that were investigated as extraction agents for rare earth (RE) metals and actinoids for the first time in the 1960s. However, more systematic investigations of their extraction properties towards REs and actinoids were not started until the 2010s. Indeed, recent studies have shown that these α-amino-functionalized compounds can outperform the commercial organophosphorus extraction agents in RE separations. They have also proven to be very efficient extraction and precipitation agents for recovering Th and U from RE concentrates. These actinoids coexist with REs in some of the commercially im…
New Insights into the Chemistry of Imidodiphosphinates from Investigations of Tellurium-Centered Systems
2010
Dichalcogenido-imidodiphosphinates, [N(PR2E)2]− (R = alkyl, aryl), are chelating ligands that readily form cyclic complexes with main group metals, transition metals, lanthanides, and actinides. Since their discovery in the early 1960s, researchers have studied the structural chemistry of the resulting metal complexes (where E = O, S, Se) extensively and identified a variety of potential applications, including as NMR shift reagents, luminescent complexes in photonic devices, or single-source precursors for metal sulfides or selenides. In 2002, a suitable synthesis of the tellurium analogs [N(PR2Te)2]− was developed. In this Account, we describe comprehensive investigations of the chemistry…
Unusual activity pattern of leucine aminopeptidase inhibitors based on phosphorus containing derivatives of methionine and norleucine
2010
Ligands containing bulky aliphatic P1 residues exhibit a high affinity towards cytosolic leucine aminopeptidase, a bizinc protease of biomedical significance. According to this specificity, a series of phosphonic and phosphinic compounds have been put forward as novel putative inhibitors of the enzyme. These phosphonic and phosphinic compounds were derivatives of methionine and norleucine as both single amino acids and dipeptides. The designed inhibitors were synthesised and tested towards the peptidase isolated from porcine kidneys using an improved separation procedure affording superior homogeneity. Unexpectedly, organophosphorus derivatives of methionine and norleucine exhibited moderat…
The cyclic [N(PiPr2E)2]+ (E = Se, Te) cations: a new class of inorganic ring system.
2006
The two-electron oxidation of [(tmeda)NaN(PiPr2E)2] with iodine produces the cyclic [N(PiPr2E)2]+ (E = Se, Te) cations, which exhibit long E–E bonds in the iodide salts. peerReviewed
A synthetic method for diversification of the P1′ substituent in phosphinic dipeptides as a tool for exploration of the specificity of the S1′ bindin…
2007
Abstract A novel, general, and versatile method of diversification of the P1′ position in phosphinic pseudodipeptides, presumable inhibitors of proteolytic enzymes, was elaborated. The procedure was based on parallel derivatization of the amino group in the suitably protected phosphinate building blocks with appropriate alkyl and aryl halides. This synthetic strategy represents an original approach to phosphinic dipeptide chemistry. Its usefulness was confirmed by obtaining a series of P1′ modified phosphinic dipeptides, inhibitors of cytosolic leucine aminopeptidase, through computer-aided design basing on the structure of homophenylalanyl-phenylalanine analogue (hPheP[CH 2 ]Phe) bound in …
Capability study of 1-butyl-3- methylimidazolium bis(trifluoromethylsulfonyl)imide and trihexyl(tetradecyl)phosphonium bis(2,4,4-trimethylpentyl)phos…
2018
Abstract The liquid-liquid equilibria of the ternary systems water (1) + 1-propanol (2) + 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([bmim][Tf2N]) (3) and water (1) + 1-propanol (2) + trihexyl(tetradecyl)phosphonium bis(2,4,4-trimethylpentyl)phosphinate ([TDTHP][Phosph]) (3) at 283.2, 303.2 and 323.2 K and atmospheric pressure were determined to study their behaviour, determine their thermodynamic parameters and know the capability as solvents of [bmim][Tf2N] and [TDTHP][Phosph] in the separation of the azeotropic mixture water + 1-propanol. The non-random two-liquid (NRTL) and universal quasichemical (UNIQUAC) models were used in the calculation of the thermodynamic par…
Experimental and Theoretical Investigations of Structural Isomers of Dichalcogenoimidodiphosphinate Dimers: Dichalcogenides or Spirocyclic Contact Io…
2007
A synthetic protocol for the tert-butyl-substituted dichalcogenoimidodiphosphinates [Na(tmeda){(EPtBu2)2N}] (3 a, E=S; 3 b, E=Se; 3 c, E=Te) has been developed. The one-electron oxidation of the sodium complexes [Na(tmeda){(EPR2)2N}] with iodine produces a series of neutral dimers (EPR2NPR2E[BOND])2 (4 b, E=Se, R=iPr; 4 c, E=Te, R=iPr; 5 a, E=S, R=tBu; 5 b, E=Se, R=tBu; 5 c, E=Te, R=tBu). Attempts to prepare 4 a (E=S, R=iPr) in a similar manner produced a mixture including HN(SPiPr2). Compounds 4 b, 4 c and 5 a–c were characterised by multinuclear NMR spectra and by X-ray crystallography, which revealed two alternative structures for these dimeric molecules. The derivatives 4 b, 4 c, 5 a an…
Networks based on hydrogen-bonds containing phosphorus anions and tris(3,5-dimethylpyrazolyl)borate nickel(II) moieties
2012
Abstract Five structural kinds of nickel hydrogen-bonded networks containing hydrotris(3,5-dimethylpyrazolyl)borate ligands (Tp∗) have been elucidated by X-ray diffraction, [Tp∗Ni(OH2)3][(p-NO2C6H4O)2PO2] (4), [Tp∗Ni(OH2)3][Me2PO2]·Me2P(O)OH (5), [Tp∗Ni(OH2)3][(nBuO)2PO2]·0.5H2O (6), [(Hpz)Tp∗Ni(OH2)2][(Ph)PO2OH] (7) and [Tp∗Ni(OH2)2(Me2PO2)] (8). The most relevant supramolecular feature of complexes 4–8 is all of them form coordination networks based on hydrogen bonds between water molecules and phosphate, phosphonate or phosphinate anions. These hydrogen bonds are formed within the monomer units in addition to connect monomers along the chains. Their behaviors in solution were investigate…
Enantiodifferentiation of N-benzyloxycarbonylaminophosphonic and phosphinic acids and their esters using cyclodextrins by means of capillary electrop…
2005
Capillary electrophoresis was successfully applied for separation of the enantiomers of N-benzyloxycarbonyl-alpha-aminophosphonic and alpha-aminophosphinic acids as well as their ethyl and phenyl monoesters with the use of a range of commercially available cyclodextrins (alpha, beta and hydroxypropyl-gamma-cyclodextrins) as chiral selectors. The dependence of effectiveness of separation on type and concentration of these chiral selectors as well as on pH of background electrolyte was examined in some detail.
Influence of Anion and Cation Structure of Ionic Liquids on Carboxylic Acids Extraction
2019
A recently proposed new mechanism and a model of reactive extraction of carboxylic acids by hydrophobic ionic liquids (ILs) was tested on five systems from published as well as from new equilibrium data on liquid-liquid extraction of butyric and lactic acids (BA and LA) from aqueous solutions. Two phosphonium and one ammonium ILs were used. The model describes experimental data for all systems with a good fit. The mechanism of acid extraction by ILs is very similar for all tested systems. This indicates a more general validity of the developed model. The model allows deeper understanding of regularities in carboxylic acid extraction by hydrophobic ILs. Stability constants of the first acid-…