Jean-Pierre Brunette

Micellar extraction of europium (III) by a bolaform extractant and parent compounds derived from 5-pyrazolone

Abstract Micellar ultrafiltration is used to determine the extraction of europium (III) by a series of micelle-solubilized extractants derived from 5-pyrazolone. The extractants, solubilized in CTAB (cetyltrimethylammonium bromide) micelles, have either a single complexing site: 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone (HPMBP), 1-phenyl-3-methyl-4-lauroyl-5-pyrazolone (HPMLP) or they are bis-ligands which can be called ‘bolaform’ extractants: 1,6-bis(1′-phenyl-3′-methyl-5′-pyrazolone-4′-)-1,6-hexanedione (HP-4-PH), 1,12-bis(1′-phenyl-3′-methyl-5′-pyrazolone-4′-)-1,12-dodecanedione (HP-10-PH). The yield of extraction is measured as a function of the pH and of the extractant/metal ratio. The efficiencies of the extractants are in the order HP-10-PH>HPMLP>HPMBP and the complex stabilities are larger than in standard solvent extraction, the former ligand giving a yield of europium extraction close to 100% at pH 2. A theoretical model is used to determine the stoichiometries of the extracted complexes, which are then compared with the situations encountered in standard solvent extraction. For the single site complexing agents the complexes formed involved three ligand molecules (L) for one metal. For the bolaform extractants the complex stoichiometries are found to be either EuL 2 H (case of HP-4-PH) or Eu 2 L 3 (case of HP-10-PH). The stoichiometries and stabilities of the complexes are discussed in relation with the confinement effect offered by the micellar particles and the effect of the local concentrations. The association of a CTA + surfactant molecule to the complex, which was suggested by previous works to ensure neutrality, appears here to be unlikely.

18C6 AND DC18C6 CROWN-ETHERS AS SYNERGIC AGENTS IN THE EXTRACTION OF Co(II) AND Ni(I) FROH CHLORIDE MEDIA WITH 1-PHENYL.-3-HETHIL.-4-BENZOYLPYRAZOL.-5-ONE IN TOLUENE

ABSTRACT The synergic extraction of Co(ll) and Ni(Il) with 1-phenyl-3-methyl-4-benzoylpyrazol-5-one (HPMBP) in presence of crown-ether (Cw) 18C6 or DC18C6 (cis-syn-cis and cis-anti-cis isomers) in toluene from 1M chloride medium is quantitatively described. A slope analysis of the distribution curves shows that the composition of the extracted species depends on the cations found in the aqueous solution : from a LiCl or (CH3.)NC14 solution, the extracted species are M(PMBP) 2.Cw (M = Co, Ni) whereas the KCw+,M(PMBP)3 ion pair is extracted from 1M KC1 solution. In the two cases, higher D-values in extraction with DC18C6 are only due to a poorer lipophilicity of 18C6; both ethers are weaker synergists than lipophilic ammonium salts.

Use of synergistic extraction for the study of atrazine/metal interactions

The ability of atrazine to interact with several metals was investigated by means of synergistic liquid–liquid extraction. For that purpose, the extraction of cadmium, copper, lead and zinc by 1-phenyl-3-methyl-4-p-tertbutylbenzoyl-5-hydroxypyrazole (HL) in chloroform was studied in the presence of atrazine (ATR). This pesticide enhanced the extraction of these metals in the order Cd>Zn>Cu through the formation of a ML2(ATR) complex. However, no influence of atrazine was observed on the extraction of lead.

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...

Synergistic extraction of cadmium and cobalt with mixtures of 4-stearoyl-pyrazol-5-ol and tri-n-octylamine in toluene

SummaryThe synergistic extraction of cobalt and cadmium (M2+) from 1M sodium perchlorate medium with mixtures of 1-phenyl-3-methyl-4-stearoyl-pyrazol-5-ol (HPMSP) and tri-n-octylammonium perchlorate (TOAH+, ClO4−) in toluene, at 25°C, has been studied. Co and Cd are extracted asM(PMSP)2 species with HPMSP alone (log12=−7.4 and −9.4 respectively), and as [TOAH−,M(PMSP)3−] species in the presence of (TOAH+, ClO4−). At high (TOAH+, ClO4−) concentrations, the synergistic equilibrium is:

SYNERGISTIC EXTRACTION OF CADMIUM AND ZINC WITH 1-PHENYL-3-METHYL-4-BENZOYLPYRAZOL-5-OL AND n-DODBCYLAMINE MIXTURES,EMULSION FORMATION.

M^{2 + } + 3\overline {HPMSP} + {\raise0.5ex\hbox{

LIQUID-GEL EXTRACTION OF U-ACYLPYRAZOL-5-ONATO COPPER COMPLEXES

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Effect of aniline derivatives on the extraction of cobalt with 1-phenyl-3-methyl-4-benzoylpyrazol-5-one in toluene

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