Solvent dependence of the stability of cryptate complexes

Cox, Brian G.; Garcia-Rosas, J.; Schneider, Hermann

doi:10.1021/ja00396a016

Cited by 137 publications

(47 citation statements)

References 7 publications

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“…A more quantitative analysis of the data requires detailed consideration of the various equilibria that are involved in these systems (15,16). This in turn reveals certain fundamental relationships which tend to be obscured when viewing only percentages of extraction, as a result of the interplay of several constituent factors which contribute to this overall result.…”

Section: Analysis Of Equilibriamentioning

confidence: 99%

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

Buncel¹,

Shin²,

Bannard³

et al. 1984

Can. J. Chem.

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The results of a comparative extraction study of potassium phenoxide, p-nitrophenoxide, and picrate, from aqueous medium into methylene chloride in the presence of crown ether and cryptand complexing agents, are reported. The efficiency of extraction varies extremely widely with the nature of the anion and the ligand. An analysis of the results in terms of constituent equilibrium constants, and the factors which influence these, is presented. The significance of the results to other areas including phase transfer catalysis is pointed out.

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Section: Analysis Of Equilibriamentioning

confidence: 99%

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

Buncel¹,

Shin²,

Bannard³

et al. 1984

Can. J. Chem.

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“…Results and Discussion (Table 1). [35] The experimental free energies of binding were determined from 1:1 binding constants from potentiometric titration experiments in previous work by Cox and co-workers. [35] Experimental enthalpies of binding were determined previously with microcalorimetry by Abraham and coworkers.…”

mentioning

confidence: 99%

“…[35] The experimental free energies of binding were determined from 1:1 binding constants from potentiometric titration experiments in previous work by Cox and co-workers. [35] Experimental enthalpies of binding were determined previously with microcalorimetry by Abraham and coworkers. [36] This trend reversal is profound because it highlights the binding multiequilibria; the binding constant is in fact a composite, information-rich term that should not be confined to a simplified two-body, host-guest interpretation.…”

mentioning

confidence: 99%

First Principles Investigation of Noncovalent Complexation: A [2.2.2]‐Cryptand Ion‐Binding Selectivity Study

Burnette

2008

ChemPhysChem

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A first principles methodology, aimed at understanding the roles of molecular conformation and energetics in host-guest binding interactions, is developed and tested on a system that pushes the practical limits of ab initio methods. The binding behavior between the [2.2.2]-cryptand host (4,7,13,16,21,24-hexaoxa-1,10-diaza-bicyclo[8.8.8]hexacosane) and alkali metal cations (Li(+), Na(+), and K(+)) in gas, water, methanol, and acetonitrile is characterized. Hartree-Fock and density functional theory methods are used in concert with crystallographic information to identify gas phase, energy-minimized conformations. Gas phase free energies of binding, with vibrational contributions, are compared to solution-state binding constants through relative binding selectivity analysis. Calculated relative binding free energies qualitatively correlated with solution state experiments only after gas phase metal desolvation is considered. The B3LYP exchange-correlation functional improves theoretical correlations with experimental relative binding free energies. The relevance of gas phase calculations towards understanding binding in condensed phases is discussed. Natural bond orbital methods highlights previously unidentified intramolecular and intermolecular M(+)(222) chemistries, such as an intramolecular n'(O)-->sigma*(CH) hydrogen bond.

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“…Probably, this can be explained by the fact that the surface of this complex is more hydrophobic as compared with all cryptates under study. As was shown in [5], this is associated with the optimal arrangement of donor atoms with respect to included cation so that the interaction of the complex with its environment is largely determined by -CH 2 -groups. Correspondingly, the effect of squeezing out from the solution volume to the interface should manifest itself to the greatest extent for…”

Section: Resultsmentioning

confidence: 83%

“…As was already mentioned in previous publications, the general picture of adsorption phenomena in systems listed above is virtually totally determined by the adsorption of cryptate cations. This conclusion is defined by the high stability of complex species ( [the constant of complex formation] is equal to 3.98, 5.47, and 4.24 for [Na + ⊂ 222], [ K + ⊂ 222 ], and [Rb + ⊂ 222 ], respectively) [5,6], so that the free ligand concentration in the solutions studied does not exceed 10 -7 -10 -8 M.…”

Section: Resultsmentioning

confidence: 99%

Estimation of parameters characterizing the adsorption of sodium, potassium, and rubidium cryptates at the mercury electrode/solution interface

Stenina

Sviridova

2005

Russ J Electrochem

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The adsorption of complexes formed by sodium, potassium, and rubidium cations with macrobicyclic ligand (kryptofix 222 with C 18 H 36 N 2 O 6 composition) is studied as a function of the ligand concentration on a stationary mercury drop in 0.1 M solutions of corresponding sulfates and chlorides by using the differential capacitance technique. Based on the model of two parallel capacitors supplemented by the Frumkin isotherm, the adsorption parameters of studied cryptates are estimated by using the regression analysis technique. Differential capacitance curves calculated with the parameters found are compared with experimental data. The comparison of the found adsorption parameters makes it possible to reveal the effects of the nature of included cations and specifically adsorbed supporting-electrolyte anions on the adsorption behavior of cryptates under study.

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Solvent dependence of the stability of cryptate complexes

Cited by 137 publications

References 7 publications

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

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

First Principles Investigation of Noncovalent Complexation: A [2.2.2]‐Cryptand Ion‐Binding Selectivity Study

Estimation of parameters characterizing the adsorption of sodium, potassium, and rubidium cryptates at the mercury electrode/solution interface

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