The extraction of alkali metal picrates by polyurethane foam using crown ether

1981 ◽  
Vol 59 (10) ◽  
pp. 1490-1496 ◽  
Author(s):  
Anjum S. Khan ◽  
W. G. Baldwin ◽  
A. Chow
Keyword(s):  
Crown Ether ◽  
Alkali Metal ◽  
Polyurethane Foam ◽  
Dissociation Constants ◽  
Extraction Constant ◽  
Ion Pair ◽  
Constant Sequence ◽  
Extraction Constants ◽  
The Stability ◽  
Ether Complex

The distribution of alkali metal picrates between water and polyurethane foam was studied in the presence of dicyclohexyl 18-crown-6 (DCHC-6). The extraction constants and dissociation constants for the ion pair (MCrA) in polyurethane foam were determined. The extraction constant sequence of the alkali metal ions with DCHC-6 is K+ > Rb+ > Cs+ > Na+ and mainly depends on the stability of the alkali metal – crown ether complex.

Extraction of alkali metal cations into polyester-based polyurethane foam using crown ether and picric acid

1987 ◽  
Vol 65 (5) ◽  
pp. 1103-1108 ◽  
Author(s):  
A. S. Khan ◽  
W. G. Baldwin ◽  
A. Chow
Keyword(s):  
Aqueous Solution ◽  
Crown Ether ◽  
Alkali Metal ◽  
Polyurethane Foam ◽  
Alkali Metals ◽  
Picric Acid ◽  
Ion Pair ◽  
Alkali Metal Cations ◽  
Degree Of Extraction ◽  
Cation Size

The distribution of alkali metal picrates between water and polyester-based polyurethane foam in the presence of dicyclohexyl-18-crown-6 was studied. The order of extraction coefficients of the alkali metals is governed by the ratio of the cation size to that of the crown ether, although the degree of extraction may depend on the nature of the organic phase. The extraction of alkali metals by polyurethane foam from an aqueous solution in the presence of crown ether and a bulky anion can be considered as an ion pair extraction of MCrA by an organic solvent.

scholarly journals Effect of substituted phenolates as a counterion on the ion-pair extraction of alkali metal ions using crown ether

2003 ◽  
Vol 52 (9) ◽  
pp. 839-842 ◽  
Author(s):  
Haruyoshi NAKAGAWA ◽  
Naoki HIRAYAMA ◽  
Takaharu HONJO
Keyword(s):  
Crown Ether ◽  
Alkali Metal ◽  
Metal Ions ◽  
Ion Pair ◽  
Alkali Metal Ions

Contribution to the thermodynamics of complexes of alkali metal cations with dibenzo-18-crown-6 in water-nitrobenzene extraction system

1984 ◽  
Vol 49 (1) ◽  
pp. 39-44 ◽  
Author(s):  
Emanuel Makrlík ◽  
Jaroslava Hálová ◽  
Miroslav Kyrš
Keyword(s):  
Alkali Metal ◽  
Alkali Metal Cation ◽  
Alkali Metal Cations ◽  
Complex Species ◽  
Cation Order ◽  
Extraction Constants ◽  
Equilibrium Data ◽  
Individual Extraction Constants ◽  
The Stability ◽  
The Individual

The stability constants for the ML+ complex species, where M+ is an alkali metal cation and L is dibenzo-18-crown-6, in nitrobenzene saturated with water were calculated by employing published equilibrium data. The stability is found to increase in the cation order Li+ < Cs+ < Rb+ < K+ < Na+. For the NaL+, KL+, RbL+, and CsL+ complex cations the individual extraction constants in the water-nitrobenzene system were determined; their values increase in the series Na+ < K+ < Rb+ < Cs+.

Ion-Pair Sorption of Alkali Metal Chlorides by Crown Ether Carboxamide Resins

1996 ◽  
Vol 31 (16) ◽  
pp. 2195-2208 ◽  
Author(s):  
Takashi Hayashita ◽  
Kenji Yamasaki ◽  
John C. White ◽  
Stanislaw P. Kasprzyk ◽  
Richard A. Bartsch
Keyword(s):  
Crown Ether ◽  
Alkali Metal ◽  
Ion Pair ◽  
Alkali Metal Chlorides ◽  
Metal Chlorides

Measurement of self-association and ion-pair dissociation constants by solvent extraction using a membrane phase separator

1982 ◽  
Vol 60 (11) ◽  
pp. 1286-1290 ◽  
Author(s):  
Murray Carmichael ◽  
Frederick F. Cantwell
Keyword(s):  
Solvent Extraction ◽  
Methylene Chloride ◽  
Dissociation Constants ◽  
Extraction Constant ◽  
Ion Pair ◽  
Membrane Phase ◽  
Dimerization Constant ◽  
Self Association ◽  
Phase Separator ◽  
Extraction Isotherms

The "filter-probe" membrane phase separator is used with a gravimetric buret to obtain the following constants at 25 °C by measuring solvent-extraction isotherms: dimerization constant of benzoic acid in chloroform (log K2,HBz = 2.12 ± 0.01); "self-ion-pair extraction" constant of Naloxone into chloroform [Formula: see text]; and ion-pair dissociation constant of tetraethylammonium picrate in methylene chloride (log Kdiss = −4.52 ± 0.09).

Extraction and transport of alkali metal salts by crown ethers and cryptands: estimation of extraction constants and their relationship to transport flux

1987 ◽  
Vol 65 (4) ◽  
pp. 884-891 ◽  
Author(s):  
Thomas Murray Fyles
Keyword(s):  
Free Energy ◽  
Alkali Metal ◽  
Crown Ethers ◽  
Extraction Constant ◽  
Metal Salts ◽  
Alkali Metal Salts ◽  
Two Phase ◽  
Extraction Constants ◽  
Polar Organic Solvent ◽  
Transport Flux

A method is described for the estimation of two phase extraction constants from stability constants for complexation of alkali metal cations by crown ethers and cryptands. The total free energy change for extraction of alkali metal salts from water to a non-polar organic solvent is evaluated as a sum of free energy terms for complexation, transfers of cation, anion, and complex between solvents, and ion pairing in the non-polar solvent. The method gives satisfactory agreement with a variety of published extraction constants and can be used predictively. As an example, the influence of extraction constant on transport flux was examined using calculated extraction constants and the rate data of Lamb etal. (J. Am. Chem. Soc. 102, 6820 (1980)); rates are adequately modelled by a simple analysis of diffusion.

NEW PHOTOMETRIC REAGENTS FOR ALKALI METAL IONS BASED ON CROWN ETHER COMPLEX FORMATION

1981 ◽  
Vol 10 (9) ◽  
pp. 1305-1306 ◽  
Author(s):  
Hiroshi Nakamura ◽  
Hideo Sakka ◽  
Makoto Takagi ◽  
Keihei Ueno
Keyword(s):  
Complex Formation ◽  
Crown Ether ◽  
Alkali Metal ◽  
Metal Ions ◽  
Alkali Metal Ions ◽  
Crown Ether Complex ◽  
Ether Complex
Sign in / Sign up

Export Citation Format

Share Document