Silver and thallium(I) complexation with dibenzo-16-crown-41Polytopic Cation Receptors, Part V. Part IV of this series, see ref [9].12Preliminary results of this work have been presented: Ouchi, M.; Liu, Y.; Hakushi, T.; Shibutani, Y.; Yakabe, K.; Shono, T. 1995 International Chemical Congress of Pacific Basin Societies, Abstracts Part II. Organic Chemistry, No. 344 (1995).2

Ouchi, Mikio; Shibutani, Yasuhiko; Yakabe, Kenji; Shono, Toshiyuki; Shintani, Hiroshi; Yoneda, Akio; Hakushi, Tadao; Weber, Edwin

doi:10.1016/s0968-0896(98)00274-0

Cited by 28 publications

(21 citation statements)

References 18 publications

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“…Calixarenes and their derivatives have attracted considerable attention as novel extractants, able to recognize and discriminate metal ions, making them suitable as specific receptors [2][3][4]. In these studies, silver(I) has been investigated more frequently than the other metals [5][6][7], including palladium and platinum and heavy metals alone or in mixtures with different noble metals [5,7]. It was found that alkali and alkaline earth metals would be coextracted readily with most calixarenes [2,4,[7][8][9][10].…”

Section: Introductionmentioning

confidence: 99%

Silver electrowinning from silver(I)–calixarene complexes by two-phase electrolysis

et al. 2007

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Results are reported, providing the basis for an elegant new process for metal recovery from acidic solutions, by integrating solvent extraction (SX) and electrowinning (EW) in a single process, rather than operating them separately, as in conventional SX-EW processes. Calixarene-tetramide and its thio-analogue were used for the extraction of silver(I) ions from aqueous phases into dichloromethane, both compounds achieving extraction efficiencies [90%. The effects were determined of extractant and silver(I) concentrations, aqueous phase pH, and the presence of sodium ions, on the distribution of Ag(I) between aqueous and organic phases. Due to the impossibility of stripping the extracted metal conventionally, electro-reductive stripping of silver(I) from the loaded organic phase was carried out in the calixarene/nitric acid two-phase system. The effects were also investigated of current density or electrode potential on silver deposition current efficiencies and cell voltages. Based on experimental data, a new process for silver(I) removal from very dilute solutions was proposed that showed high percentage extractions of silver(I) from the aqueous phase, coupled to direct EW of silver from the calixarene complex in the loaded organic phase, regenerating the extractant for recycle. Current efficiencies in the range from 60% to 90% and cell voltages \3.5 V were achieved simultaneously in this process.

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Section: Introductionmentioning

confidence: 99%

Silver electrowinning from silver(I)–calixarene complexes by two-phase electrolysis

et al. 2007

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“…Synthesized lariat ethers with thiazole side-arms [10] extract silver, predominantly, from a mixture of Na, K, Pb, Cu, and Cd metal perchlorates. Dibenzo-16-crown-4 [11] was also selective for silver, and thallium, over other alkali metal picrates examined. By use of a chloroform solution of dibenzo-18-crown-6 as carrier, silver has been separated from Cu by means of facilitated transport with 0.1 mol L -1 thiourea solution at pH 1 [12].…”

Section: Introductionmentioning

confidence: 90%

Use of dicyclohexano-18-crown-6 to separate traces of silver(I) from potassium thiocyanate in hydrochloric acid media, and determination of the silver by atomic absorption spectrometry

Camagong

Honjo

2002

Anal Bioanal Chem

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Solvent extraction with 0.05 mol L(-1) dicyclohexano-18-crown-6 (DC18C6) in 1,2-dichloroethane, coupled with flame atomic absorption spectrometry (AAS), has been investigated as a new method for separation of trace amounts of silver(I) from 0.05 mol L(-1) potassium thiocyanate in 1.0 mol L(-1) hydrochloric acid media and quantification of the amount of silver present. The method is based on the formation of an extractable ion-association product, [DC18C6.K](+)[Ag(SCN)(2)](-), with a metal-to-crown ether ratio of 1:1 (as derived from slope analysis data). Stripping of the extracted silver(I) in the 1,2-dichloroethane phase was achieved within 5 min by use of 3.0 mol L(-1) potassium thiocyanate. Reducing the concentration of acid in the sample solution to 0.1 mol L(-1) improved the preconcentration factor severalfold. Excellent tolerance of the proposed method to the presence of foreign ions in solution with silver(I) was demonstrated. A detection limit of 13 ng mL(-1) was derived from the mean value of the blank plus three times its standard deviation. The method was used to determine traces of silver(I) after separation from gold(III), platinum(IV), and palladium(II) matrices on the basis of extractability differences with 18-membered crown ethers under specified conditions. The efficiency of the adopted ion-association mechanism for silver(I) extraction was apparent from the average recovery of 96% for spiked standards by use of the back-washing technique. The proposed extraction procedure was applied to the determination of traces of silver(I) in a selection of chemical reagents.

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“…The crown ethers have been found to be powerful extracting agents for the alkali and alkali-earth metals [5][6][7][8]. The cation-binding ability of a crown ether, and its cation selectivity, depend on: the size and charge density of the cation, the size and flexibility of the crown ether, the number and the nature of the substituted groups on the macrocyclic ring, the character and number of the donor atoms, the nucleophilicity of the counterion, and the nature of the solvent [9]. The introduction of the substituents into crown ether molecules affects their spectral, photochemical, and complexing properties [10].…”

Section: Introductionmentioning

confidence: 99%

Double‐Armed Benzo‐15‐crown‐5 Ligands and Complexes and Single Crystal Structure Determination

Şahin

Süzen

Hayvalı

2013

Heteroatom Chemistry

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This work describes the syntheses and characterizations of double‐armed benzo‐15‐crown‐5 containing nitro (1), amine (2), and imine (3–5) groups, and their sodium complexes (1a–5a). Structures of the ligands (1–5) and sodium complexes (1a–5a) were identified via elemental analyses, and infrared, 1H‐ nuclear magnetic resonance (NMR), 13C‐NMR, and mass spectrometry. The metal extractions were examined by using ultravoilet–visible spectrophotometry. Single crystal for 2 was successfully obtained, and its X‐ray crystal structure was resolved. The compound 2 crystallizes in triclinic, space group p‐1 with a = 9.1420(3), b = 14.9580(4), c = 20.4110(5), and Z = 4.

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Cited by 28 publications

References 18 publications

Silver electrowinning from silver(I)–calixarene complexes by two-phase electrolysis

Silver electrowinning from silver(I)–calixarene complexes by two-phase electrolysis

Use of dicyclohexano-18-crown-6 to separate traces of silver(I) from potassium thiocyanate in hydrochloric acid media, and determination of the silver by atomic absorption spectrometry

Double‐Armed Benzo‐15‐crown‐5 Ligands and Complexes and Single Crystal Structure Determination

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