Extraction and separation studies of platinum(IV) with N-n-octylaniline

Lokhande, Tukaram N.; Anuse, Mansing A.; Chavan, M. B.

doi:10.1016/s0039-9140(98)00172-6

Cited by 42 publications

(23 citation statements)

References 9 publications

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“…2À extraction by long-chain alkylamines have shown that mixing periods ranging from several minutes (e.g., between 1-5 mins for Alamine 304 and N-n-octylaniline) [24,25] to several hours (e.g., overnight for trioctylamine) [23] may be necessary to achieve equilibrium. To determine the optimum mixing time, a chloroform phase containing L 8 and an acidic, aqueous phase containing [H 2 PtCl 6 ] were contacted at room temperature for varying periods of time.…”

Section: Mixing Time Studies: Previous Studies Of the Equilibrium Timmentioning

confidence: 99%

Selective Extraction and Transport of the [PtCl₆]²⁻Anion through Outer‐Sphere Coordination Chemistry

Warr

Westra

Bell

et al. 2009

Chemistry A European J

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A series of tripodal receptors designed to recognise the outer coordination sphere of the hexachlorometallate anion [PtCl(6)](2-), and thus show selectivity for ion-pair formation over chloride binding, has been synthesised and characterised. The tripodal ligands contain urea, amido or sulfonamido hydrogen-bond donors, which are aligned to bind to the regions of greatest electron density along the faces and edges of the octahedral anion. The ligand structure incorporates a protonatable bridgehead nitrogen centre that provides a positive charge to ensure the solubility of a neutral 2:1 [LH](+)/[PtCl(6)](2-) complex in water-immiscible solvents. The extraction of [PtCl(6)](2-) from acidic chloride solutions was evaluated by using a pH-swing mechanism to control the loading and stripping of the metallate anion. The ligands L(1)-L(3), L(5)-L(9), L(11)-L(13) and L(15) showed extremely high loading (up to 95% in some cases) and high selectivity for [PtCl(6)](2-) over chloride ions (present in a 60-fold excess) compared with trioctylamine, a model Alamine reagent, which, under identical conditions, only extracted 10% of the Pt(IV) anions. Generally, extraction was observed to be greater for urea-containing ligands than their amido analogues, and a quantitative recovery of platinum from feed solutions was achieved. The formation of neutral ([LH](+))(2)[PtCl(6)](2-) packages in organic media is supported by single-crystal X-ray structure determinations of [(L(2)H)(2)PtCl(6)] x 2 CH(3)CN, [(L(8)H)(2)PtCl(6)(MeOH)(2)], [(L(12)H)(2)PtCl(6)] x 2 CH(3)CN and [(L(14)H)(2)PtCl(6)], which confirm the presence of significant hydrogen bonding between the anion and urea or amido moieties of the protonated ligand and the anion. The structure of [(L(1)H)(H(3)O)PtCl(6)] x C(6)H(6) x CH(3)CN shows hydrogen bonding of a H(3)O(+) cation to the receptor and confirms that other stoichiometries are also possible, indicating that speciation in solution may be more complex.

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Section: Mixing Time Studies: Previous Studies Of the Equilibrium Timmentioning

confidence: 99%

Selective Extraction and Transport of the [PtCl₆]²⁻Anion through Outer‐Sphere Coordination Chemistry

Warr

Westra

Bell

et al. 2009

Chemistry A European J

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“…The extraction mechanism corresponds to an anion exchange, in which a complex of stoichiometric formula (R 3 NH + ) 2 PtCl 6 2− is formed in the organic phase liberating at the same time Cl − ions in the aqueous phase [9]. Some extractants are reported for extraction separation of platinum from palladium [10][11][12][13][14][15][16][17][18][19][20] but very less number of extractants is utilized for separation of platinum from rhodium [21,22]. The LLE literatures reviewed showed that, despite a large number of studies, no system has been identified as yet to yield quantitative extraction of rhodium from concentrated solutions [23][24][25][26][27].…”

Section: Introductionmentioning

confidence: 99%

Liquid–liquid extraction/separation of platinum(IV) and rhodium(III) from acidic chloride solutions using tri-iso-octylamine

Lee

Kumar

Kim

et al. 2009

Journal of Hazardous Materials

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“…Equation (2) suggests that the slope of the straight line in a plot of log D against log [R 3 N] should be about two. However, the slope of the straight lines in Fig.…”

Section: )mentioning

confidence: 99%

“…The most prominent feature of the aqueous chemistry of platinum group metals in chloride solution is the strong tendency of the metals to form anion complexes with chloride ion. 2) Since the concentration of platinum group metals in industrial wastes is very low, ion exchange and solvent extraction have been widely employed to separate and recover them. Solvent extraction of Pt(IV) with various extractants has been reported.…”

Section: Introductionmentioning

confidence: 99%

Solvent Extraction of PtCl<SUB>4</SUB> from Hydrochloric Acid Solution with Alamine336

Lee

Kumar

et al. 2008

Mater. Trans.

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We have conducted solvent extraction of Pt(IV) from HCl solution with Alamine336. Solvent extraction reaction in our system was determined from the experimental results by graphical method. The equilibrium constant of the solvent extraction reaction was estimated from our experimental results by considering the activity coefficients of chemical species present in the aqueous phase with Bromley equation. Bromley interaction parameter between hydrogen ion and PtCl 2À 6 was evaluated from the solvent extraction data reported in the literature. Solvent extraction of PtCl 4 by Alamine336 and the corresponding equilibrium constant in our experimental range can be represented by PtClThe measured distribution coefficients of Pt(IV) agreed well with those calculated in this study.

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Extraction and separation studies of platinum(IV) with N-n-octylaniline

Cited by 42 publications

References 9 publications

Selective Extraction and Transport of the [PtCl₆]²⁻Anion through Outer‐Sphere Coordination Chemistry

Selective Extraction and Transport of the [PtCl₆]²⁻Anion through Outer‐Sphere Coordination Chemistry

Liquid–liquid extraction/separation of platinum(IV) and rhodium(III) from acidic chloride solutions using tri-iso-octylamine

Solvent Extraction of PtCl<SUB>4</SUB> from Hydrochloric Acid Solution with Alamine336

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Extraction and separation studies of platinum(IV) with N-n-octylaniline

Cited by 42 publications

References 9 publications

Selective Extraction and Transport of the [PtCl6]2−Anion through Outer‐Sphere Coordination Chemistry

Selective Extraction and Transport of the [PtCl6]2−Anion through Outer‐Sphere Coordination Chemistry

Liquid–liquid extraction/separation of platinum(IV) and rhodium(III) from acidic chloride solutions using tri-iso-octylamine

Solvent Extraction of PtCl<SUB>4</SUB> from Hydrochloric Acid Solution with Alamine336

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Selective Extraction and Transport of the [PtCl₆]²⁻Anion through Outer‐Sphere Coordination Chemistry

Selective Extraction and Transport of the [PtCl₆]²⁻Anion through Outer‐Sphere Coordination Chemistry