A PC compatible computer program for the calculation of equilibrium constants by the simultaneous processing of different sets of experimental results

Vetrogon, Victor; Luk’yanenko, N. G.; Schwing‐Weill, Marie‐José; Arnaud‐Neu, Françoise

doi:10.1016/0039-9140(94)00187-1

Cited by 79 publications

(42 citation statements)

References 12 publications

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“…[26] As evidence was only found for 1:1 complexes, b 11 can be abbreviated in the following text as b. The values given in the data tables correspond to the arithmetic means of at least three independent determinations.…”

Section: Stability Constant Determinationsmentioning

confidence: 99%

Extraction and Complexation of Alkali, Alkaline Earth, and F-Element Cations by Calixaryl Phosphine Oxides

et al. 1999

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A series of new calixarene derivatives with phosphine oxide groups on the lower rim and, for comparison, a series of noncalixarene phosphine oxides have been synthesised. Their extraction power for alkali and alkaline earth cations from aqueous metal picrate solution into dichloromethane have been determined as well as the stability constants in methanol of the 1:1 complexes of several members of the calixarene series. Important selectivity trends are revealed by both methods. The extraction power from aqueous nitrate solutions (1m in HNO 3 ) towards europium(iii), as a model for trivalent actinides, and thorium(iv), as a model for tetravalent actinides, has been studied in detail for eight symmetrical calixarene derivatives, which differ in either calixarene size (4, 5, 6 or 8), the substituent at the upper rim (tert-butyl or hydrogen) or the number of methylene groups separating the phenolic oxygen atoms from the phosphorus atoms (1 or 2). The stoichiometry of the extracted species was characterised by a classical log ± log plot analysis. All the calixarenes tested are far better extractants than typical noncalixarene extractants, for example, TOPO and CMPO, currently in use in the treatment of radioactive waste; they extract thorium better than europium. The influence of the nitric acid concentration and of the sodium nitrate concentration in the aqueous phase on the extraction efficiency was also examined in order to assess the possible application of these compounds for the decategorisation of liquid nuclear waste. Several thorium complexes have been characterised by their stability constants in methanol.

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Section: Stability Constant Determinationsmentioning

confidence: 99%

Extraction and Complexation of Alkali, Alkaline Earth, and F-Element Cations by Calixaryl Phosphine Oxides

et al. 1999

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“…1.0 mM ligand solutions containing one equivalent of the metal cation with a concentrated Et 4 NOH solution. The titration data were interpreted using the programs Sirko 18 and Hyperquad. 19 The protonation constants of the L 3-ligands, previously determined from titrations without the metal ions, were held constant during the refinement procedure.…”

Section: Issn 1551-7012mentioning

confidence: 99%

Tri-ionizable calix[4]arene ligands: synthesis and lanthanide ion complexation

Fernandez¹,

Bartsch²,

Arnaud‐Neu³

et al. 2010

Arkivoc

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“…The protonation constants of the ligands and the complexation constants b xyz corresponding to the general complexation equilibrium xM n+ + yL + zH + 76 47 M x L y H z (nx + z)+ were determined from the pH-metric data obtained in the course of neutralization of an acidic solution of the ligand with 0.01 M Et 4 NOH in MeOH in an argon flow in the presence of metal salts or without them. The data were processed with the SIR-KO program [19] allowing simultaneous determination of the constants b xyz , electrode parameters, and concentrations of the mixture components. For calculations, we used the total titration curve in the range pH 3312.…”

Section: Nn`-bis(hydroxyethyl) Diaza Crown Ethers Vii3mentioning

confidence: 99%

Synthesis and Complexing Properties of N,N′-Bis(2-hydroxyethyl) Diaza Crown Ethers

Kulygina¹,

Vetrogon²,

Basok³

et al. 2005

Russ J Gen Chem

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The stability constants of complexes of 12-, 15-, and 18-membered diaza crown ethers, N,N`-dimethyl diaza crown ethers, and N,N`-bis(2-hydroxyethyl) diaza crown ethers with alkali and alkaline-earth metal ions in 95% aqueous methanol at 25oC were determined. The stability of the complexes of unsubstituted diaza crown ethers with alkali metal cations is low, probably because of stabilization of the exo,exo conformation of the ligands due to interaction of the nitrogen lone electron pairs with the solvent. The complexes with the double-charged cations are appreciably more stable. N,N`-Dimethyl diaza crown ethers form stable complexes with all the ions studied. As compared to the dimethyl derivatives, N,N`-bis(2-hydroxyethyl) diaza crown ethers form more stable complexes with the Na + , K + , Ca 2+ , Sr 2+ , and Ba 2+ ions, which is due to participation of the side hydroxyethyl groups in the coordination.Macrocyclic polyethers with side groups containing donor atoms (lariat crown others) can form complexes with a three-dimensional coordination sphere, similar to that in cryptates, since the donor atoms of both the macroring and the side chains can be involved in the coordination. This gives rise to unusual complexing properties, which do not directly correlate with the extent of size matching between the cation and macroring cavity but strongly depend on the structure of side substituents [135]. In this respect, N-hydroxyethyl aza crown ethers are among the most interesting representatives of lariat ethers. In these compounds, the terminal hydroxy groups (or alkoxy groups in the case of N-alkoxyethyl derivatives) usually participate in the coordination with a cation [6 39]. However, despite the fact that a large set of such crown ethers have been studied, their complexing properties have been examined for only a limited number of alkali and alkaline-earth cations (mainly Na + , K + , and Ca 2+ ). The data were obtained in different solvents and by different methods, which prevents a comprehensive analysis of the influence exerted on the complexation by the ring structure and kind of the cation.To find how the substituents at the N atoms affect the complexation and whether the side hydroxyethyl groups participate in the coordination with cations, we studied under identical conditions the interaction of unsubstituted diaza crown ethers I3III, N,N`-dimethyl diaza crown ethers IV3VI, and N,N`-bis(2-hydroxyethyl) diaza crown ethers with alkali and alkalineearth metal ions. For diaza crown ethers I3VI, data are available on the stability constants of the complexes with only a few alkali and alkaline-earth metal ions [10].N,N`-Dimethyl diaza crown ethers IV3VI were prepared by reductive methylation of I3III with formaldehyde in formic acid, following the protocol described in [11] (see scheme).The most common route to N-hydroxyethyl aza crown ethers is the reaction of aza crown ethers with oxirane [12]. It is advisable to perform the reaction in water with a twofold excess of oxirane. The optimal reaction conditions shoul...

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A PC compatible computer program for the calculation of equilibrium constants by the simultaneous processing of different sets of experimental results

Cited by 79 publications

References 12 publications

Extraction and Complexation of Alkali, Alkaline Earth, and F-Element Cations by Calixaryl Phosphine Oxides

Extraction and Complexation of Alkali, Alkaline Earth, and F-Element Cations by Calixaryl Phosphine Oxides

Tri-ionizable calix[4]arene ligands: synthesis and lanthanide ion complexation

Synthesis and Complexing Properties of N,N′-Bis(2-hydroxyethyl) Diaza Crown Ethers

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