Electron transfer (ET) kinetic rate constants k s in Ethaline (1:2 Choline Chloride + Ethylene Glycol) have been measured for two common redox couples (ferrocene/ferrocenium and ferrocyanide/ferricyanide) on a glassy carbon electrode and compared with ET kinetics in ionic liquids and classical organic solvents in the same conditions (acetonitrile and water). A particular care has been taken to treat ohmic drop in DES. For both couples, we found that ET rate constants are just a little lower than those measured in classical solvents (around 50% or less). These results contrast with ET rates in ionic liquids where electron transfers are considerably slower (100 times lower). Data are discussed as function of the solvent relaxation time using Marcus Theory for an adiabatic electron transfer.

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A rapid and easy solvent free one-pot synthesis of 5-arylidene-2-imino-4-thiazolidinones by condensation of the thioureas with chloroacetic acid and an aldehyde under microwave-irradiation is described.

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Classical electrochemical approaches were evaluated for investigating the basic properties of deep eutectic solvents (DES) with a special focus on the mass transport phenomena and diffusion of charged species in DES. Three classical DES were considered: Reline, Ethaline and cholinechloride-lactic acid mixture. Cyclic voltammetries of the ferrocene oxidation and of the ferricyanide reduction, respectively with charge 0 and -3, exhibit well-defined responses in these media. For all considered DES and redox molecules, diffusion processes govern the masstransport of the redox molecules from the solution to the electrode. Derived diffusion coefficients were extracted and found to present some inconstancies with the classical StokesEinstein law for homogeneous media. The diffusion coefficients were found to be almost unaffected by the charge present on the diffusing molecules contrarily to observations made for ionic liquids.

deltif Amrane, et al.. Assessment of VOC absorption in hydrophobic ionic liquids: Measurement of partition and diffusion coefficients and simulation of a packed column. Chemical Engineering Journal, Elsevier, 2019, 360, pp. AbstractPartition coefficients of toluene and dichloromethane (DCM) in 23 hydrophobic ionic liquids (ILs), which can be used potentially for the physical absorption of volatile organic compounds (VOCs), were measured at 298 K. The partition coefficients, expressed as Henry's law constants, were 400 to 1300 times for toluene and 10 to 47 times for DCM lower in the selected ILs than in water. Thus, the toluene and DCM diffusion coefficients were measured in three high potential hydrophobic ILs and in [Bmim][NTf 2 ] using a thermogravimetric microbalance. Diffusivity measurements were performed at 298K for toluene and between 278 and 308K for DCM. Diffusion coefficients in ILs, ranging between 1 and 4×10 -11 m 2 s -1 , were from 18 to 90 times lower than in water at 298 K. The diffusion coefficients were correlated to the temperature, the solute molar volume, the IL viscosity and molar volume with an average error of 4.2%. Finally, a 3 m industrial packed column was simulated for the removal of DCM and toluene in [AllylEt 2 S][NTf 2 ] and [bmim][NTf 2 ], which both present moderate viscosities of nearly 50 mPa s at 293K. The overall mass-transfer coefficient, the removal efficiency and the pressure drop were calculated and compared to those obtained using other heavy solvents (a silicon * Corresponding author : pierre-francois.biard@ensc-rennes.fr, Tel: + 33 2 23 23 81 49 2 oil and di-(2-ethylhexyl) adipate). This prospective simulation has demonstrated a good potential of ionic liquids for the toluene removal. Nonetheless, the DCM removal efficiencies simulated were lower than 44%. It suggests that even more efficient ionic liquids can be tuned and synthesized in the future for this specific application. Highlights Toluene partition coefficients in 23 ILs were in the range 0.5-3.5 Pa m 3 mol -1  Dichloromethane partition coefficients in 23 ILs were in the range 5-17 Pa m 3 mol -1  VOC diffusion coefficients in the range 1-4×10 -11 m 2 s -1 were measured in 4 ILs  The computed toluene removal efficiency in a packed column was from 52 to 99.6%  The computed dichloromethane removal efficiency in a packed column was lower than 44% Graphical abstractVicious air containing VOC: Treated air Ionic liquid Loaded ionic liquid Metal Pall rings 3.0 m 1.0 m •Toluene •Dichloromethane Operating conditions Hydrodynamics Mass-transfer rate (K l a°) Pressure drop Removal efficiency Solvent assessment for VOC removal in a packed column Partition coefficient Diffusion coefficient Ionic liquid properties (m, r, s) Static headspace method Static thermogravimetric method Measurements Simulation •[bmim][NTf 2 ] •[AllylEt 2 S][NTf 2 ] Finally, the hydrodynamics and mass-transfer in a packed column fed with [Bmim][NTf 2 ] and [AllylEt 2 S][NTf 2 ] were simulated for DCM and toluene absorption. * AR is the affinity r...

We have performed small angle neutron scattering (SANS) in a momentum transfer range (0.05 < Q < 0.5 Å -1 ) to study long range order and concentration fluctuations in deep eutectic solvents (DESs) and their aqueous solutions. Ethaline (choline chloride:ethylene glycol), glycerol:lactic acid, and menthol:decanoic acid mixtures were selected to illustrate respectively the case of ionic, nonionic and hydrophobic mixtures. Different carefully designed isotopic labelling was used to emphasize selectively the spatial correlations between the different solvent components. For ethaline DESs and their aqueous solutions, a weak low-Q peak observed only for certain compositions and some partial structure factors revealed the mesoscopic segregation of ethylene glycol molecules that do not participate to the solvation of ionic units, either because they are in excess with respect the eutectic stoichiometry (1:4 neat ethaline) or substituted by water 2 (4w-ethaline and higher aqueous dilutions). For the nonionic hydrophilic solutions, such a mesoscopic segregation was not observed. This indicates that the better balanced interactions between the three nonionic H-bonded components (water, lactic acid, and glycerol) favor homogeneous mixing. For the hydrophobic DESs, we observed an excess of coherent scattering intensity centered at Q = 0, which could be reproduced by a model of non-interacting spherical domains. Local concentration fluctuations are not excluded either. However, unlike liquid mixtures with a tendency to demix, we have found no evidence of expansion of domains with different compositions to a large scale.