Gibbs Transfer Energies of Ions from a Mixed Solvent of 2H,3H-Decafluoropentane and 1,2-Dichloroethane to Water

Abstract

The transfer of hydrophilic, lipophilic, and fluorophilic ions at the interface between water (W) and a mixed solvent (MIX) of 2H,3H-decafluoropentane (DFP) and 1,2-dichloroethane (DCE) was studied voltammetrically and potentiometrically, and the formal Gibbs transfer energies of the ions from MIX to W, ΔG 0 tr, ′ MIX→W, were determined. The ΔG 0 tr, ′ MIX→W values of all the ions tested were higher than those from DFP to W. Namely, the ions would exist more stably in MIX than DFP, even for fluorophilic ions. This is due to the addition of DCE, which has a higher dielectric constant. A comparison of ΔG 0 tr, ′ MIX→W with that from DCE to W showed a superior affinity of fluorophilic ions to the fluorous solvent in spite of equivolume addition of DCE. Therefore, the mixed solvent would be a practically superior extraction medium for fluorophilic ions. In practice, the MIX | methylene blue + (W) system showed higher extractability of a fluorophilic ion C8F17SO3than the DFP | W and DCE | W systems.

Light-induced electron transfer/phase migration of a redox mediator for photocatalytic C–C coupling in a biphasic solution

“…Hence, the Gibbs energies for the migration of the ion pair Fc + A − (Δ G (Fc + A − ) DCE→H 2 O ) can be tuned by the Gibbs energy for phase migration of added anion (Δ G (A − ) DCE→H 2 O ) on the basis of eqn (4). 54 Δ G (Fc + A − ) DCE→H 2 O = Δ G (Fc + ) DCE→H 2 O + Δ G (A − ) DCE→H 2 O …”

A Theoretical Approach to the Fluorophilicity of Ions via the Gibbs Energy of Ion Transfer at the Fluorous Solvent/Water Interface

“…In fact we could obtain valuable information for understanding the characteristic intermolecular interactions of fluorous molecules. that were previously reported for 14 fluorinated anions [7][8][9] (however, the data for an anion, 2, have been revised). The corresponding values for 12 non-fluorinated cations [7][8][9] and 16 non-fluorinated anions 7,9 are shown in Tables S1 and S2 (Supporting Information).…”

“…In previous papers, [6][7][8][9] our group reported the applicability of a fluorous solvent, DFP (2H,3H-or 1,1,1,2,3,4,4,5,5,5-decafluoropentane), as a non-aqueous solvent for liquidliquid electrochemistry. Using the polarized DFP/water (W) interface, the apparent or formal Gibbs energies 10 were then compared with those from W to non-fluorinated organic solvent such as nitrobenzene (NB) and 1,2-dichloroethane (DCE).…”

Ion-Transfer Voltammetry at Fluorous Ether | Water Interfaces

“…In fact, we have reported that an mixed solvent consisting of DFP and DCE becomes a useful solvent for extraction of a highly fluorinated ion compared to DCE. 10 However, DFP's boiling point is as low as 66ºC, and its volatilization often made the experiment difficult. Therefore, other fluorous solvent, especially low volatile one, would be desirable.…”

“…were listed inTable 2together with the reported values of the formal Gibbs transfer energy for DFP, Although the estimated values of G 0 tr ' ,F→W might be affected by the ionpair formation in the F phase, the values still seem to be useful as a quantitative measure of the affinity of ions for the fluorous solvent 6,9,10. TheFigure5 shows the plots of G 0 tr ' ,F→W for TFE (triangle) and OFE (square), against G 0 tr ' ,DCE→W .…”