Correlation between the standard Gibbs energies of an anion transfer from water to highly hydrophobic ionic liquids and to 1,2-dichloroethane

0424224 - ÚFCH JH 2015 RIV CH eng J - Článek v odborném periodiku
Langmaier, Jan - Samec, Zdeněk - Samcová, E. - Tůma, P.
Correlation between the standard Gibbs energies of an anion transfer from water to highly hydrophobic ionic liquids and to 1,2-dichloroethane.
Journal of Electroanalytical Chemistry. 714-715, FEB 2014 (2014), s. 109-115. ISSN 1572-6657. E-ISSN 1873-2569
Grant CEP: GA ČR GAP206/11/0707
Institucionální podpora: RVO:61388955
Klíčová slova: ionic liquid * 1,2-dichloroethane * Cyclic voltammetry
Kód oboru RIV: CG - Elektrochemie
Impakt faktor: 2.729, rok: 2014

Cyclic voltammetry is used to investigate the transfer of several semihydrophobic and hydrophilic anions (F-, Cl-, Br-, I-, View the MathML source, View the MathML source, SCN-, View the MathML source, View the MathML source, View the MathML source) across the polarized interface between an aqueous electrolyte solution and a highly hydrophobic ionic liquid (IL) membrane. Three ILs are examined being composed of the trioctadecylmethylammonium (TOMA+), tridodecylmethylammonium (TDMA+) or tetradodecylammonium (TDA+) cation and the tetrakis[3,5-bis(trifluoromethyl)phenyl]borate (TFPB-) anion. The standard Gibbs energies of the anion transfer from water to IL, View the MathML source, are evaluated from the voltammetric measurements by applying the classical tetraphenylarsonium-tetraphenylborate hypothesis. Comparison of data for various ILs points to a small systematic effect of the cationic IL component, which is manifested by somewhat lower values of View the MathML sourcefor most anions in the presence of TDMA+ or TDA+, indicating their stronger association with the anions. The capillary electrophoresis measurements suggest that the degree of interaction of anions with the IL cations in water could follow the order TDMA+ > TOMA+ > TDA+. It is shown that a linear correlation with the nearly unity slope between View the MathML source and the standard Gibbs energy of anion transfer from water to 1,2-dichloroethane (DCE), View the MathML source, can be established for all three ILs studied. An extended correlation including both the present and the literature values of View the MathML source for the ion transfer from water to TDMATFPB reveals the consistency of data for the semihydrophobic cations and anions, and the presence of a weak solvation effect favoring the transfer of hydrophilic anions (F-, Cl-, Br-, I-) and disfavoring the transfer of hydrophilic cations (H+, Li+, Na+, K+, Rb+, Cs+).
Trvalý link: http://hdl.handle.net/11104/0230262