Ligand Function of Ion-Selective Electrodes Reversible to Zinc and Cobalt Thiocyanate Complexes: Causes of Formation, Mathematical Description, and Analytical Applications

Matveichuk, Yu. V.; Рахманько, Е. М.

doi:10.1134/s106193481905006x

Cited by 3 publications

(3 citation statements)

References 9 publications

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“…Conveniently, the cation and the anion were expanded to investigate the role of the structure in the reversible NH 3 uptake of the PILs by taking advantage of the designable structure of the IL’s unit. It’s reported the tetrahedral Cu/Zn(SCN) 4 2– , − whose crystal structure were investigated through DFT study, their structures are similar to tetrahedral Co(II) with thiocyanate anion . Pyridinium is a commonly used cation in ILs.…”

Section: Results and Discussionmentioning

confidence: 99%

Role of Structure in the Ammonia Uptake of Porous Polyionic Liquids

Luo

et al. 2022

ACS Sustainable Chem. Eng.

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In this work, tunable NH 3 uptake of polyionic liquids (PILs) are reported through regulating the size of the cross-linking agent R, the metallic anion M(II) (SCN) 4 2− , where M are Co, Zn, and Cu, and the cationic polymer framework of PILs. Combined with NH 3 uptake experiments, spectroscopic analysis, and DFT calculation, the NH 3 uptake was proposed as the coordination with M(II) to generate M(NH 3 ) n 2+ , where n = 6 when M = Co and n = 4 when M = Cu and Zn, which suggests that the NH 3 capacity is dominated by the metal center for different coordinative numbers. The increase in the size of R benefits the high capacity of NH 3 uptake for more metallic anions to be exchanged and promotes NH 3 desorption for the enhancement of porosity of PILs; however, the oversize of R goes against porosity and NH 3 desorption. There seems to be less effect of the cation on ammonia uptake, while the stable cationic polymer framework protects the PILs from collapse. Overall, the tunable porosity (surface area of 15.9−869.0 m 2 /g and total volume of pores of 0.011−0.695 cm 3 /g) and NH 3 uptake properties (capacity of 11.6−20.1 mmol/g PIL) as well as feasible NH 3 desorption of PILs are realized for the flexible structural design of PILs. Furthermore, the adsorbed H 2 O and SO 2 on NH 3 uptake of PVIm-R8-Co were investigated. The investigation in this work makes the role of the structure of PILs in ammonia uptake clearer and provides the designability of PILs for gas adsorption and other applications.

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Section: Results and Discussionmentioning

confidence: 99%

Role of Structure in the Ammonia Uptake of Porous Polyionic Liquids

Luo

et al. 2022

ACS Sustainable Chem. Eng.

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“…К настоящему времени имеется большое количество публикаций, посвященных вопросам теории функционирования и практического применения электродов с лигандной функцией. В частности, изучены роданидные функции электродов, обратимых к ионам [2][3][4][5][6][7][8][9][10][11][12] и [9][10][11][12], хлоридные и бромидные функции электродов, обратимых к галогенидным комплексам [13],…”

Section: Introductionunclassified

Theoretical description of the ligand function for ionoselective electrodes reversible to metal anion complexes. 1. Lower detection limit and its determining factors

Егоров¹,

Семенов²,

Novakovskii³

et al. 2020

Journal of the Belarusian State University. Chemistry

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Within the framework of the steady-state diffusion model, the theoretical description for the thiocyanate ion lower detection limit (LDL) by the tetrathiocyanatozincate selective electrode, has been presented. The main assumptions of this model are constancy of the ion exchanger concentration along the membrane, traditionally used in various phaseboundary potential diffusion models, and linear profiles of components’ concentrations in diffusion layers. Simple quantitative expressions have been obtained, connecting thiocyanate ion concentration in the solution surface layer (responsible for LDL value) with phase boundary extraction equilibria constants, stability constants for zinc thiocyanate complexes, and diffusion parameters in the membrane and solution phases. Calculated LDL values are in good agreement with experimental data provided in the literature. It has been shown that LDL can be reduced substantially by controlling such easily regulated diffusion parameters as diffusion layer thickness in the membrane phase, which is a function of time, and diffusion layer thickness of the sample solution, which is governed by stirring regime.

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“…Многие ионоселективные электроды (ИСЭ), обратимые к анионным комплексам металлов, проявляют так называемую лигандную функцию -зависимость потенциала от концентрации ионов лиганда в исследуемом растворе, в котором концентрация соответствующего металла постоянна либо равна нулю [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. Отличительной особенностью ИСЭ с лигандной функцией, представляющей существенный практический интерес, является сверхнернстовский наклон, а также многократное улучшение селективности к ионам лиганда относительно посторонних анионов, не образующих комплексов с соответствующим металлом.…”

Section: Introductionunclassified

Theoretical description of the ligand function for ionoselective electrodes reversible to metal anion complexes. 2. Selectivity to foreign ions

Егоров¹,

Семенов²,

Novakovskii³

et al. 2020

Journal of the Belarusian State University. Chemistry

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Within the framework of the steady-state diffusion model, the equations have been obtained explicitly describing the selective electrode selectivity coefficient to the ligand ion in relation to foreign ions not forming complexes with zinc ions, as a function of fundamental thermodynamic characteristics (exchange constants of tetrathiocyanatozincate for thiocyanate and foreign ion, concentrations of ion exchanger in the membrane and zinc ion in the sample solution), as well as controllable diffusion parameters (thicknesses of solution and membrane phase diffusion layers, governed by stirring mode and measuring time, respectively). Separate attention is given to cases of measurements in presence and in absence of constant background concentration of zinc ions in the sample solution. It has been shown that selectivity of tetrathiocyanatozincate selective electrode to thiocyanate ion in relation to anions not forming complexes with zinc, is several orders of magnitude higher than selectivity of an ordinary thiocyanate-selective electrode containing higher quaternary ammonium thiocyanate as an ion exchanger, and increases regularly with the background concentration of zinc ions. The results obtained are in general agreement with the experimental data given in the literature. It has been shown that variability of selectivity coefficients caused by variations of diffusion parameters within the limits corresponding to real measuring conditions, can be up to 0.3–0.4 orders of magnitude.

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Ligand Function of Ion-Selective Electrodes Reversible to Zinc and Cobalt Thiocyanate Complexes: Causes of Formation, Mathematical Description, and Analytical Applications

Cited by 3 publications

References 9 publications

Role of Structure in the Ammonia Uptake of Porous Polyionic Liquids

Role of Structure in the Ammonia Uptake of Porous Polyionic Liquids

Theoretical description of the ligand function for ionoselective electrodes reversible to metal anion complexes. 1. Lower detection limit and its determining factors

Theoretical description of the ligand function for ionoselective electrodes reversible to metal anion complexes. 2. Selectivity to foreign ions

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