G. J. Goetz-Grandmont

SYNERGISTIC EXTRACTION OF COPPER (II) AND OTHER DIVALENT METALS WITH 3-PHENYL-4-ACYLISOXAZOL-5-ONES AND 1-PHENYL-3-METHYL-4-ACYLPYRAZOL-5-ONES IN THE PRESENCE OF TRI-n-OCTYLPHOSPHINE OXIDE IN TOLUENE

ABSTRACT The synergistic extraction of copper (II) from 1M NaN03 aqueous solutions with acidic chelating extractants HL = 3-phenyl-4-acylisoxazol-5-ones (acyl = benzoyl, HPBI, and p-tert-butylbenzoyl, HPtbBI) and 1-phenyl-3-methyl-4-acylpyrazol-5-ones (acyl = benzoyl, “HPMBP”, p-tert-butylbenzoyl, “HPMtbBP” and stearoyl, HPMSP), in the absence and presence of trx-n-octylphosphine oxide (TOPO) in toluene at 25°0, has been studied. The TOPO-HL interaction, which is one order of magnitude stronger with 4-acylisoxazol-5-ones than with 4-acylpyrazol-5-ones, strongly influences the synergistic extraction efficiency. The extracted species are CuL2 and CuL2(T0P0). Because of their higher acidity, the extractions performed with 4-acylisoxazol-5-ones occur at a lower pH range than with 4-acylpyrazol-5-ones.

ANALYTICAL AND SPECTROSCOPIC STUDY OF ZINC EXTRACTION WITH 1, 10-BIS[1-PHENYL-3-METHYL-5-HYDHOXY-1-PYFAZOLYL]-1,10-DECANEDIONE AND THI-n-OCTYLPHOSPHINE OXIDE.

Abstract Zinc extraction from perchlorate medium, with 1, 10-bis[ 1-phenyl-3-methyl-5-hydroxy-4-pyrazolyl]-1,10-decanedione (HL-8-LH) and its mixtures with tri-n-octylphoaphine oxide (TOPO) in chloroform has been investigated and compared with the corresponding extraction systems with 1-phenyl-3-methyl-4-benzoyl-pyrazol-5-ol (HL*). The extraction processes are: Zn2+ + 2 HL-8-LH 3* 2 H+ + Zn(L-8-LH) (K ) -3.24(25°) and -2.80(30°); log K 121= -2.35(25°); log Ki: ±0.1. HL-8-LH is a slightly better extractant than HL, due to the higher lipophilicity of the extracted complexes. For high values of [Zn], in both extraction systems, a third solid phase forms: it consists of the bis-chelate Zn(L-8-L)(H2O) (IR study). A quantitative PMR study of synthetic solutions “Zn(L-8-L)(H2O) + × TOPO”, in wet CDC13, gives evidence of the occurrence of the complexes Zn(L-8-L)(TOPO) and Zn(L-8-L)(TOPO)2. Only the former is clearly characterized in the extraction phases. In those systems, the influence of coordination upon TOP...

MOLECULAR MODELLING AND SPECTROSCOPIC STUDIES OF THE INTERACTIONS BETWEEN CHELATING AND ELECTRON-DONOR METAL EXTRACTANTS: THE SYSTEM TRI-N-OCTYLPHOSPHINE OXIDE - 3-PHENYL-4-BENZOYL-ISOXAZOL-5-ONE ( ‘HPBI‘ ) IN WET TOLUENE AND CHLOROFORM.

ABSTRACT IR, NMR (H, 13C and 31P) and electronic spectroscopies have been used to study the tautomeric forms of 3-phenyl-4-benzoyl-isoxazol-5-one, HPBI, and its interaction with tri-rc-octylphosphine oxide, ‘TOPO’, in wet toluene or benzene, and in chloroform. These metal extracting media have been compared with analogous solutions containing l-phenyl-3-methyI-4-acyI-pyrazoI-5-oIs. The spectroscopic results are compared with those of molecular modelling studies. Spectroscopic criteria that allow a choice between the various tautomeric forms of pyrazolones or isoxazolones are briefly reviewed. In the solid, in wet toluene, benzene or chloroform solutions, HPBI mainly exists as a fi-keto-enol chelate, quite different from its tautomeric form in methanol, which is most probably a diketone-enamine. Molecular modelling studies show that the energy difference between the chelated 5-hydroxy- and 5-one- tautomeric forms of the free molecule is rather low. They cannot be discriminated by spectroscopy As shown by...

SYNERGISTIC EXTRACTION OP CADMIUM AND ZINC FROM NITRATE MEDIUM WITH 3-PHENYL-4-BENZOYLISOXAZOL-5-ONE IN THE PRESENCE OF METHYL-TRI-n-OCTYLAMMONIUM NITRATE IN CHLOROFORM AND TOLUENE

ABSTRACT The synergistic extraction of cadmium and zinc, from 1M NaN03 aqueous solutions, with the acidic chelating extractant 3-phenyl-4-benzoylisoxazol-5-one (HPBI), in the presence of the nitrate salt of aliquat 336 (methyl-tri-n-octylammonium nitrate named TOMA.NO3), has been studied in chloroform and toluene. The extracted species are TOMA.M(PBI)3 with M = Cd, zn. The synergistic extraction is described by the following equilibria: The difference observed between toluene and chloroform is mainly due to the higher distribution constant of HPBI in chloroform (logKd = 3.0) than in toluene (logKd = 2.3). The Zn extraction is more enhanced by TOMA.NO3 than the Cd one, contrary to what is observed in the synergistic extraction using 1-phehyl-3-methyl-4-benzoylpyrazol-5-one (HPMBP).

EXTRACTION OF ZINC AND CADMIUM WITH SOME BIS(5'-HYDROXY-PYRAZOL-4'-OYL)ALKANES AND TRI-n-OCTYLPHOSPHINE OXIDE IN CHLOROFORM

ABSTRACT The extraction of zinc and cadmium with bis(5‘-hydroxy-pyrazol-4’-oyljalkanes (“HL-n-LH”, n: number of methylene links), with and without TOPO, in chloroform, has been studied when possible. The formation of third phases and/or precipitates hinders a number of extractions with HL-n-LH alone: CdII for all extractants, ZnII for n < 7. The following species are extracted with cadmium: Cd(L-n-L) (TOPO)2 for n = 5, 7 to 10, Cd(L-8-L)(TOPO), Cd(L-8-LH)2(TOPO)2, Cd(L-8-LH)2(TOPO), and with Zn: Zn(L-n-LH)2 for n = 7 and 8, Zn(L-n-L) for n = 9 and 10, Zn(L-n-LH)2(TOPO) for n = 5 and 7, Zn(L-n-L) (TOPO) for n = 7 to 9. The polymethylene chain length effect upon the extraction processes is attributed to a relative destabilization of Zn(L-n-L) with respect to Zn(L-n-LH)2 for short-chain ligands, and conversely, to a preferential solvation of Zn(L-n-LH)2(TOPO)x complexes by chloroform. The former may be due to some strain in the tetradentate ligand folded onto zinc. The latter is attributed to H-bond formatio...

Synthesis and Characterization of Mesostructured Silica Doped with Acyl‐Hydroxy‐Pyrazole Derivatives. Sorption Tests of Cu(II) and Eu(III)

Abstract The synthesis and the characterization of mesostructured silica doped with acidic acyl‐hydroxy‐pyrazoles like extractants are described. The extractants have either a single chelating site, 1‐phenyl‐3‐methyl‐4‐stearoyl‐5‐hydroxy‐pyrazole (HPMSP), or two chelating sites, 1,12‐bis(1′‐phenyl‐3′‐methyl‐5′‐hydroxy‐4′‐pyrazolyl)‐dodecane‐1,12‐dione (HL‐10‐LH). The so‐called doped silicas were synthesized in basic medium according to a sol‐gel process beginning with the solubilization of the extractant in a micellar phase followed by the precipitation of silica around micelles. The chemical composition of the synthesized materials, especially the ligand content, was determined. High quantities of ligand loadings (up to 0.69 mol/kg) are reached. The materials obtained were characterized by X‐ray diffraction, laser granulometry, transmission and scanning electron microscopy and, after calcination, by nitrogen physisorption. Un‐doped silica is mesostructured, lamellar, and has high pore diameter as well as high specific surfaces. Doping induces the disorganization of the lamellar structure, the increase of the pore diameter, and a slight decrease of the specific surface. The capacities of extraction of Cu(II) and Eu(III) by the doped materials and the corresponding extraction rate were measured: high values are reached.

Solid‐Liquid Extraction of Lanthanum(III), Europium(III), and Lutetium(III) by Acyl‐Hydroxypyrazoles Entrapped in Mesostructured Silica

Abstract The solid‐liquid extraction of lanthanum(III), europium(III), and lutetium(III) by mesostructured silicas doped with 1‐phenyl‐3‐methyl‐4‐stearoyl‐5‐pyrazolone (HPMSP, bearing one chelating site) or with 1,12‐bis(1′‐phenyl‐3′‐methyl‐5′‐hydroxy‐4′‐pyrazolyl)‐dodecane‐1,12‐dione (HL‐10‐LH, bearing two chelating sites) has been studied and compared to the analogous solvent and micellar extractions in terms of the stoichiometry of the extracted complex and of the extraction efficiency. The solid‐liquid extraction order in the lanthanoid series is La<Eu<Lu; it is the usual liquid‐liquid extraction order obtained with acidic extractants. A theoretical model is used to determine the stoichiometries of the extracted complexes and the extraction yield is measured as a function of the pH, of the extractant/metal ratio (S/M) and of the volume ratio of the two phases (φ). For HPMSP, the extracted complexes involve three ligand molecules for one metal. For HL‐10‐LH, the complex stoichiometries are found to be either Ln(L‐10‐L)(L‐10‐LH) (Ln=La, Eu) or Lu2(L‐10‐L)3 for S/M=25, or Eu2(L‐10‐L)3 for S/M=5. For the first time, the synergistic solid‐liquid extraction is studied after a successful attempt at simultaneously immobilizing both extractants HL‐10‐LH and 2,4,6‐tri(2‐pyridyl)‐1,3,5‐triazine, “TPTZ”, into silica; the complex extracted in this case differs from the one obtained in solvent extraction.

EXTRACTION OF INDIUM( III) FROM BROMIDE AND THIOCYANATE MEDIA WITH 1-PHENYL-3-HETHYL-1-BENZOYLPYRAZOL-5-ONE; EFFECT OF LIPOPHILIC AMMONIUM SALTS

ABSTRACT 1-phenyl-3-methyl-4-benzoylpyrazol-5-one (HL) in toluene extracts In(III) from ClO4 −, (Br−, CIO ClO4 −, ) and Br− media according to the extraction equilibria (1) and (2). Tri-n-octylmethylammonium bromide (B+Br−) induces a medium synergic effect for Br− and (Br−,NO3 −) media, which is cancelled in ClO4 −medium. It corresponds to the extraction of (B+InBrxL4-x) ion pairs. On the contrary, from SCN− or (SCN−,ClO4 −) media, In is extracted by HL according to only (1) and no synergism is obtained with tri-n-octylammonium salt. These results are compared with those obtained with Cl− and (C1−,ClO4 −) aqueous media. They are to a great extent explained by taking into account the complexing of In3+ by aqueous inorganic anions, the lipophilicity of the diverse species and the anionic exchanges in the B+X− ion pairs.

Folding onto Copper(II) of a Flexible Bis-Chelating 4-Acyl-pyrazol-5-olate

The structure of {1,10-bis[5-(hydroxy-κO)-3-methyl-1-phenyl-4-pyrazolyl]decane-1,10-dionato(2-)-κ 2 O 1, 10 }-copper(II), [Cu(C 30 H 32 N 4 O 4 )], has been determined. It consists of two types of [Cu{L-(CH 2 ) 8 -L}] mononuclear unit (HL = 5-hydroxy-3-methyl-1-phenyl-4-pyrazoloyl functional group), characterized by different conformations of the polymethylene chain. Both molecules contain a Cu atom in an almost square-planar environment of O atoms [1.907 (8) < Cu-O < 1.939 (8) A]. All acylpyrazolonate moieties are planar within experimental error. The phenyl rings make angles in the range 2-28° with the corresponding pyrazole planes. In the first type of [Cu{L-(CH 2 ) 8 -L}] moiety (1), the two chelating subunits and the metal plane adopt a stepped conformation, whereas in the second [Cu{L-(CH 2 ) 8 -L}] moiety (2), one of the two chelating subunits and the metal plane are coplanar. The mononuclear units form centrosymmetric dimers (1,1) and (2,2), in which the Cu atoms may be viewed as five-coordinate [Cu...O = 2.546 (8) and 2.463 (9) A, respectively, in (1,1) and (2,2)]

SPECTROSCOPY OF INDIUM(III) LIPOPHILIC SPECIES EXTRACTABLE FROM PERCHLORATE MEDIUM BY TWO 1-PHENYL-3-METHYL-4-ACYL-PYRAZOL-5-OLS AND TRI-N-OCTYLPHOSPHINE OXIDE*

ABSTRACT With the aim of improving our knowledge about the extraction of indium from perchlorate media, by 1-phenyl-3-methyl-4-acyl-pyrazol-5-ols, “HL” ( acyl = benzoyl or thenoyl) and their mixtures with tri-n-octylphosphine oxide, “TOPO”, in toluene, synthetic and extraction organic phases, and extractable conplexes, have been studied by phosphorus-31 and proton NMR, and by IR spectroscopy. As expected from the extraction equilibria, only one species is extracted by HL. It is identified as a tris-chelate by comparison with the synthesized complexes InL3(H2O)z (z = 0, 2). The synergistic mixtures HL + x TOPO extract several species InL3(TOPO)n ( n.≥. 0, depending upon x). A coordination number of In higher than 6 is suggested. The only way to obtain strong In − O = PR3 bonds is the extraction of indium, therefore, the reaction: