Comparative extraction studies of potassium phenoxide, <i>p</i>-nitrophenoxide, and picrate into methylene chloride by macrocyclic crown ether and cryptand complexing agents

Buncel, Erwin; Shin, H. S.; Bannard, R. A. B.; Purdon, J. G.

doi:10.1139/v84-152

Cited by 13 publications

(9 citation statements)

References 10 publications

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“…Calculation of the fraction of M2+ (or X-) extracted into the organic phase via eqs. [4] and [5] is considered in the discussion.…”

Section: Resultsmentioning

confidence: 99%

“…All solutions (aqueous and organic), however, were analysed by uv, and any AIOH present was readily distinguished from AIO-by virtue of its different absorption maxima. In other respects the extraction procedure was as previously described (5,6). Control experiments showed that none of the nitrophenoxide salts were extracted in the absence of ligand.…”

Section: Extraction Proceduresmentioning

confidence: 99%

“…This is especially true when the charge on the accompanying anion is highly delocalized as, for example, in the picrate anion (1)(2)(3)(4)(5)(6).…”

Section: Introductionmentioning

confidence: 99%

“…phenoxide, and picrate from aqueous medium into methylene chloride in the presence of crown ether and cryptand complexing agents (5). In a parallel systematic study, the extraction of potassium phenoxide with macrocyclic ligands from aqueous medium into diverse organic solvents was investigated (6).…”

Section: Introductionmentioning

confidence: 99%

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Extraction of alkaline-earth metal ortho- and para-nitrophenoxides from aqueous media by crown ether and cryptand complexing agents

Cox¹,

Buncel²,

Shin³

et al. 1986

Can. J. Chem.

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. Can. J. Chem. 64,920 (1986).A study has been performed on the extraction of alkaline-earth metal ortho-and para-nitrophenoxides, from aqueous medium into methylene chloride, in the presence of crown ether and cryptand complexing agents. The results are analyzed in terms of the various constituent complexation and extraction equilibria involved. Comparison is drawn with our previously reported study on extraction of potassium p-nitrophenoxide. The different anion stoichiometries in the two systems result in relatively more favorable extraction of M+ systems at low anion concentrations. Furthermore, while extraction of MX (X = o-or p-nitrophenoxide) can be carried out in the presence of excess MOH, this is not possible in the case of MX2 due to the limited solubility of M(OH)2. The addition of excess MOH leads to more efficient extraction of M+-phenoxides and prevents hydrolysis to free phenols. A noteworthy point in both MX and MX2 systems is that at high concentrations of complexing agent a saturation effect occurs, which limits the overall extent of extraction achievable. Under these conditions the extraction is governed by the equilibrium constant, Kdcs, representing the partitioning of the complexed salt between the aqueous and organic phases, and is independent of the amount of ligand present. [Traduit par la revue] Introduction Efficient extraction of alkali-metal salts from aqueous media into organic solvents is often observed in the presence of macrocyclic complexing agents. This is especially true when the charge on the accompanying anion is highly delocalized as, for example, in the picrate anion (1-6).Studies of extraction equilibria have considerable practical importance in relation to phase-transfer catalysis (7,8) and analytical applications (9), and are also frequently used for comparative purposes in estimating the complexing capabilities

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“…Calculation of the fraction of M2+ (or X-) extracted into the organic phase via eqs. [4] and [5] is considered in the discussion.…”

Section: Resultsmentioning

confidence: 99%

Section: Extraction Proceduresmentioning

confidence: 99%

“…This is especially true when the charge on the accompanying anion is highly delocalized as, for example, in the picrate anion (1)(2)(3)(4)(5)(6).…”

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Extraction of alkaline-earth metal ortho- and para-nitrophenoxides from aqueous media by crown ether and cryptand complexing agents

Cox¹,

Buncel²,

Shin³

et al. 1986

Can. J. Chem.

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“…1 Jawaid and Ingman 2 as well as Buncel et al 3 had reported an ion-pair extraction of NaA, KA, and CaA2 by dicyclohexano-18-crown-6 ether (DCH18C6) into CH2Cl2, where HA = 2,5-dinitrophenol, 2,6-dinitrophenol (H + 2,6-Dnp -), dipicrylamine, phenol, picric acid (HPic), or p-nitrophenol. Thereby, they had shown that the extraction constants (Kex/mol -2 dm 6 ) or ion-pair extraction ones (Kex,ip/mol -1 dm 3 ) for ion-pair complexes (ML + A -) vary with the nature of A -.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of the Hydrophilic Properties of Crown Ether-ion-pair Complexes with Alkali Metal Picrates by Their Distribution into Less-polar Diluents

2009

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Partition coefficients of crown ethers

Stolwijk

Vos

Sudhölter

et al. 1989

Recl. Trav. Chim. Pays‐Bas

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Abstract. Benzo and dibenzo crown ethers become more water soluble as the number of oxyethylene units increase. Moreover, the solubility in water is larger than expected on the basis of calculations using empirical models, viz., "the fragment model" and "the substituent model". New hydrophobic fragmental constants of the oxyethylene fragment, f(-OCH,CH,-) = -0.17, and of the veratrole fragment, f [C6H4(OCH2-)2] = 0.99, for the system 1-octanol/water have been determined experimentally. Using these values, reliable partition coefficients of macrocyclic polyethers can be calculated. Comparison of the benzo crown ethers with the open-chain model compounds surprisingly did not reveal a macrocyclic effect on the partition coefficient.

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Comparative extraction studies of potassium phenoxide, p-nitrophenoxide, and picrate into methylene chloride by macrocyclic crown ether and cryptand complexing agents

Cited by 13 publications

References 10 publications

Extraction of alkaline-earth metal ortho- and para-nitrophenoxides from aqueous media by crown ether and cryptand complexing agents

Extraction of alkaline-earth metal ortho- and para-nitrophenoxides from aqueous media by crown ether and cryptand complexing agents

Evaluation of the Hydrophilic Properties of Crown Ether-ion-pair Complexes with Alkali Metal Picrates by Their Distribution into Less-polar Diluents

Partition coefficients of crown ethers

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