scholarly journals Extraction of Sodium Picrate by 3m-Crown-mEthers and Their Monobenzo Derivatives (m= 5, 6) into Benzene: Estimation of Their Equilibrium-Potential Differences at the Less-Polar Diluent/Water Interface by an Extraction Method

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Yoshihiro Kudo ◽  
Tsubasa Nakamori ◽  
Chiya Numako
Keyword(s):  
Extraction Method ◽  
Ion Pair ◽  
Equilibrium Potential ◽  
Straight Line ◽  
Extraction Constants ◽  
Distribution Constants ◽  
The Individual ◽  
Polar Diluent ◽  
O Phase ◽  
Complex Ion

Individual distribution constants (KD,A) of picrate ion (Pic−) and extraction constants (Kex±) of NaPic by some crown ethers (L) into benzene (Bz) at 25°C were calculated from data reported previously. These constants were defined asKD,Pic=Pic-o/[Pic-]andKex±=NaL+oPic-o/(Na+Lo[Pic-]), respectively. Here, the subscript “o” denotes an organic (o) phase and practically o = Bz. 15-Crown-5 ether (15C5), 18-crown-6 one (18C6), and their monobenzo (B) derivatives (B15C5 and B18C6) were selected as L. Interfacial equilibrium-potential differences (Δϕeq) at extraction were estimated at 298 K. A plot oflog⁡Kex±versus-Δϕeqfor the four L extraction systems gave a straight line with slope = 84 V−1. This slope was compared with those, reported before, of the dichloromethane (DCM), 1,2-dichloroethane (DCE), and nitrobenzene (NB) extraction systems. The slopes of the regression lines were in the order NB < DCM ≤ DCE < Bz. Also, the individual distribution constants of the complex ionNaL+and an ion-pair complex (NaL+Pic-) into Bz phase were calculated from the above extraction data. At least, a comparison between these values suggests that Bz molecules mainly interact withNaL+moiety ofNaL+Pic-.

Extraction of Selected Lanthanoids and Scandium with Bis(2-ethylhexyl)hydrogenphosphate in 1,1,2,2-Tetrachlorodifluoroethane

1992 ◽  
Vol 57 (8) ◽  
pp. 1647-1654 ◽  
Author(s):  
Petr Sládek ◽  
Oldřich Navrátil ◽  
Petr Linhart
Keyword(s):  
Solid Phase ◽  
Metal Chelates ◽  
Organic Medium ◽  
Extraction Constants ◽  
Distribution Constants ◽  
The Individual

A study was made of the extraction of Ce, Pm, Eu, Tm and Sc(III) from aqueous into organic medium of 1,1,2,2-tetrachlorodifluoroethane (CFC-112) using bis(2-ethylhexyl)hydrogenphosphate (HDEHP) as extracting reagent. On the basis of earlier work which demonstrated the usefulness of using this type of solvent for extractions with dibutylhydrogenphosphate (HDBP) and also the possibility of using CFC-112 for converting the metal chelates formed to the solid phase, the work was concentrated particularly on the dependence of the extraction of selected lanthanoids on the analytical concentration of HDEHP and also on the [H+] concentration. In addition the dimerization and distribution constants were determined for this reagent in a mixture of CFC-112 with benzene and the extraction constants were determined for the individual metals.

scholarly journals Determination of Distribution Equilibrium-Potential Differences Based on Extraction with Several Crown Ethers by Nitrobenzene, 1,2-Dichloroethane and Dichloromethane

2017 ◽  
Vol 9 (4) ◽  
pp. 110 ◽  
Author(s):  
Yoshihiro Kudo ◽  
Tomohiro Amano ◽  
Satoshi Ikeda
Keyword(s):  
Complex Formation ◽  
Conditional Distribution ◽  
Equilibrium Constants ◽  
Formation Constants ◽  
Equilibrium Potential ◽  
Complex Formation Constants ◽  
Extraction Constants ◽  
Distribution Constants ◽  
Extraction Equilibria

Extraction constants (Kex± & Kex) were determined at 298 K for the extraction of sodium picrate (NaPic) by nitrobenzene (NB), 1,2-dichloroethane (DCE) and dichloromethane using 3m-crown-m ethers and their benzo-derivatives (m = 5, 6; abbreviated as L) together with the determination of conditional distribution constants (KD,Pic) of picrate ion, Pic-, into these diluents. The K1,org (= [NaLPic]org/[NaL+]org[Pic-]org) values at the organic (org) phases, such as NB & DCE, were calculated from the relation Kex/Kex± = K1,org. Distribution equilibrium-potential differences (Dfeq) at extraction equilibria were evaluated from the equation Dfeq = -0.05916´(log KD,Pic - constant) at 298 K. Correlations of the above equilibrium constants, particularly Kex±, with Dfeq were examined. Furthermore, the standard formal potentials for Na+ transfers across the interfaces were briefly evaluated from calculated Dfeq, [Na+] and [Pic-]org. The above extraction systems were characterized by K1,org and the complex formation constants of Na+ with L in the org phases.

scholarly journals Pb(II) Extraction with Benzo-18-Crown-6 Ether into Benzene under the Co-Presence of Cd(II) Nitrate in Water

Inorganics ◽  
2018 ◽  
Vol 6 (3) ◽  
pp. 77 ◽  
Author(s):  
Yoshihiro Kudo ◽  
Tsubasa Nakamori ◽  
Chiya Numako
Keyword(s):  
Ionic Strength ◽  
Conditional Distribution ◽  
Equilibrium Constants ◽  
Water Phase ◽  
Equilibrium Potential ◽  
Extraction Constants ◽  
Distribution Constants

Extraction of Pb(II) with picrate ion [Pic−] and 0, 0.58, 15, 48, or 97 mmol dm−3 Cd(NO3)2 by benzo-18-crown-6 ether (B18C6; L as its symbol) into benzene (Bz) was studied. Three kinds of extraction constants, Kex, Kex±, and KPb/PbL (or Kex2±), were determined at 298 K: these constants were defined as [PbLPic2]Bz/P, [PbLPic+]Bz[Pic−]Bz/P, and [PbL2+]Bz/[Pb2+][L]Bz (or [PbL2+]Bz([Pic−]Bz)2/P), respectively. The symbol P shows [Pb2+][L]Bz[Pic−]2 and the subscript “Bz” denotes the Bz phase, Bz saturated with water. Simultaneously, conditional distribution constants, KD,Pic (=[Pic−]Bz/[Pic−]), of Pic− with distribution equilibrium-potential differences (dep) were determined. Then, based on the above four constants and others, the component equilibrium constants of K1,Bz (=[PbLPic+]Bz/[PbL2+]Bz[Pic−]Bz), K2,Bz (=[PbLPic2]Bz/[PbLPic+]Bz[Pic−]Bz), and KD,PbL (=[PbL2+]Bz/[PbL2+]) were obtained. Using these constants, the Pb(II) extraction with B18C6 under the co-presence of Cd(II) in the water phase was characterized. In such a characterization, I and IBz dependences on the constants were mainly discussed, where their symbols denote the ionic strength of the water phase and that of the Bz one, respectively.

Examination of the Conditions of Extraction of Toxic Organic Bases and of Methods of Their Determination. III. Extraction of Ion-Associates of Dibenz[b,f]-1,4-oxazepin

1994 ◽  
Vol 59 (3) ◽  
pp. 582-588
Author(s):  
Jan Souček ◽  
Ladislav Belický ◽  
Josef Havel
Keyword(s):  
Aqueous Phase ◽  
Basic Dye ◽  
Organic Bases ◽  
Safranine T ◽  
Extraction Constants ◽  
Distribution Constants

The protonation and distribution constants of dibenz[b, f]-1,4-oxazepin (CR) were measured. This substance forms stable ion-associates with Acid Red 88, extractable into chloroform. Reextraction with an aqueous phase containing basic fuchsine or safranine T brings about exchange of the CR cation for the basic dye cation. The associates so formed exhibit higher conditional extraction constants and higher molar absorptivities than the initial associates.

Extraction of rare earth metals from trichloroacetate solutions in the presence of linear polyoxonium compounds

1991 ◽  
Vol 56 (8) ◽  
pp. 1585-1592 ◽  
Author(s):  
Petr Vaňura
Keyword(s):  
Rare Earth ◽  
Nonionic Surfactant ◽  
Separation Factor ◽  
Rare Earth Metals ◽  
Extraction Constants ◽  
Distribution Constants ◽  
Factor Α

Extraction of rare earth metals from lithium trichloroacetate solutions ( 1.20-2.88 mol l-1) with solutions of the commercial nonionic surfactant Slovafol 909 (p-nonylphenylnonaethylene glycol) in chloroform and dichloromethane was investigated. The extraction constants as well as the Slovafol 909 distribution constants were determined in the water-dichloromethane and water-chloroform systems. The lanthanide distribution ratios decrease with their atomic numbers first rather rapidly (approximately to Sm): the separation factor αSmLa = 1.54 and 1.87 in dichloromethane and in chloroform, respectively; for lanthanides with higher atomic numbers the drop is less pronounced (αLuLa = 2.42 and 2.85 in the two solvents, respectively).

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.

Preparation and characterization of cobalt-containing P,N-ligands and an unusual palladium complex ion pair: their applications in amination reactions

Tetrahedron ◽  
2008 ◽  
Vol 64 (40) ◽  
pp. 9507-9514 ◽  
Author(s):  
You-Chen Hsiao ◽  
Wen-Yuan Chiang ◽  
Chia-Ming Weng ◽  
Fung-E. Hong
Keyword(s):  
Palladium Complex ◽  
Ion Pair ◽  
Complex Ion

Hydrogen-bonded complex-ion-pair equilibriums in 3,4-dinitrophenol-amine-aprotic solvent systems

1972 ◽  
Vol 76 (14) ◽  
pp. 1989-1993 ◽  
Author(s):  
R. A. Hudson ◽  
R. M. Scott ◽  
S. N. Vinogradov
Keyword(s):  
Aprotic Solvent ◽  
Ion Pair ◽  
Solvent Systems ◽  
Complex Ion ◽  
Hydrogen Bonded
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