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The mechanisms governing the interactions of neutral polar solutes with ions in aqueous solutions are still poorly understood, despite the importance of this phenomenon in many fields (chemistry, physicochemistry, biology, food industries). In order to go further through the understanding of the molecular mechanisms governing the ions’ specific effects, this paper presents a generic method dealing with the characterization and understanding of interactions between saccharides and ions in aqueous systems. For that, an original approach combining a computational technique and experimental measurements (thermodynamic properties) is proposed to explain and rationalize the relationship between the solute hydration and the physical chemistry of the ions in solution (cation/anion, charge, size, and hydration). These relationships make it possible to evaluate the hydration state of a saccharide, a polar neutral molecule, according to the ionic composition, from the knowledge of the ions’ hydration properties. This work proposes new insight into molecular mechanisms governing the polar neutral solute/ion interactions and a new understanding of the hydration phenomenon in electrolytic solutions., A new understanding of the mechanisms governing the solute interactions in electrolyte solution is proposed. Saccharide hydration can be predicted and tuned via knowledge of the ions’ properties.

A promising method of Carbon dioxide (CO2) valorization is to use green microalgae photosynthesis to process biofuel. Two Phase Partitioning Bioreactors (TPPBR) offer the possibility to use non-aqueous phase liquids (NAPL) to enhance CO2 solubility; thus making CO2 available to maximize algae growth. This requires relatively less toxic hydrophobic Ionic Liquids (ILs) that comprise a new class of ionic compounds with remarkable physicochemical properties and thus qualifies them as NAPL candidates. This paper concerns the synthesis of ILs with octyl and butyl chains as well as different cations containing aromatic (imidazolium, pyridinium) and non-aromatic (piperidinum, pyrrolidinium) rings for CO2 absorption studies. The authors measured their respective toxicity levels on microalgae species, specifically, Scenedesmus quadricauda, Chlorella vulgaris and Botryococcus braunii. Results revealed that octyl-based ILs were more toxic than butyl-based analogues. Such was the case for bmim-PF6 at double saturation with an absorbance of 0.11, compared to Omim-PF6 at 0.17, bmim-NTf2 at 0.02, and Omim-NTf2 at 0.14, respectively. CO2 uptake results for ILs bearing octyl-based chains compared to the butyl analog were 54% (nCO2/nIL) (i.e., moles of CO2 moles of IL) and 38% (nCO2/nIL), respectively. Conclusively, 1-butyl-1-methylpiperidinium absorbed 13% (nCO2/nIL) and appeared the least toxic, having an absorbance of 0.25 at 688 nm (double saturation at 7 d) compared to 1-butyl-3-methylimidazolium, which showed the highest toxicity with zero absorbance. Accordingly, these findings suggest that 1-butyl-1-methylpiperidinium is capable of transporting CO2 to a system containing green microalgae without causing significant harm; thus allowing its use in TPPBR technology.

International audience; Sodium phosphates are generally synthesized by neutralization of orthophosphoric acid with sodium hydroxide. In this paper, we communicate a new synthesis process, wherein sodium dihydrogen phosphate can be obtained from sodium chloride and orthophosphoric acid, using cation resin exchange at room operational conditions. This opens a new concept for the design of environmentally friendly processes in this inorganic synthesis field.

International audience; This study is devoted to the characterization of ion exchange inside a microsphere of carboxylic resin. It aims at describing the kinetics of this exchange reaction which is known to be controlled by interdiffusion in the particle. The fractional attainment of equilibrium function of time depends on the concentration of the cations in the resin which can be modelized by the Nernst−Planck equation. A powerful approach for the numerical resolution of this equation is introduced in this paper. This modeling is based on the work of Helfferich but involves an implicit numerical scheme which reduces the computational cost. Knowing the diffusion coefficients of the cations in the resin and the radius of the spherical exchanger, the kinetics can be hence completely determined. When those diffusion parameters are missing, they can be deduced by fitting experimental data of fractional attainment of equilibrium. An efficient optimization tool coupled with the implicit resolution has been developed for this purpose. A monovalent/trivalent cation exchange had been experimentally characterized for a carboxylic resin. Diffusion coefficients and concentration profiles in the resin were then deduced through this new model.

This paper aims to illustrate the rich potential of the thioether-carboxyl combination in generating coordination networks with tunable and interesting structural features. By simply varying the ratio between Cu(NO(3))(2) and the bifunctional ligand tetrakis(methylthio)benzenedicarboxylic acid (TMBD) as the reactants, three coordination networks can be hydrothermally synthesized in substantial yields, which present a distinct evolution with regard to metal-ligand interactions. Specifically, Cu(TMBD)(0.5)(H(2)TMBD)(0.5)·H(2)TMBD (1) was obtained with a relatively small (1:1) Cu(NO(3))(2)/TMBD ratio, and crystallizes as an one-dimensional (1D) coordination assembly based on Cu(I)-thioether interactions, which is integrated by hydrogen-bonding to additional H(2)TMBD molecules to form a three-dimensional (3D) composite network with all the carboxylic acid and carboxylate groups remaining uncoordinated to the metal ions. A medium (1.25:1) Cu(NO(3))(2)/TMBD ratio leads to compound Cu(2)TMBD, in which Cu(I) ions simultaneously bond to the carboxylate and thioether groups, while an even higher (2.4:1) Cu(NO(3))(2)/TMBD ratio produced a mixed-cation compound Cu(II)(2)OHCu(I)(TMBD)(2)·2H(2)O (2), in which the carboxylic groups are bonded to (cupric) Cu(II) ions, and the thioether groups to Cu(I). Despite the lack of open channels in 2, crystallites of this compound exhibit a distinct and selective absorption of NH(3), with a concomitant color change from green to blue, indicating substantial network flexibility and dynamics with regards to gas transport.

The hydrogen-loss channel, induced by sequential multiphoton absorption, of the vapor-phase fluorene cation was investigated using a supersonic molecular beam and a time-of-flight mass spectrometer. The fluorene cation was prepared by resonantly enhanced multiphoton ionization. The ultimate goal of this experiment is the determination of the evolution of the dissociation rate constant in a wide energy range. In this paper, we give a description of the original experimental procedure, show that the absorption process is non-Poissonian, and determine the absolute photon absorption cross section.

The so-called ‘catanionic’ vesicles are made from mixtures of cationic and anionic surfactants. They are attracting much interest because they form spontaneously and they can be obtained from a variety of surfactants, either commercially available or issued from original synthesis. A distinction can be made between the properties of simple surfactant mixtures and of ion pair amphiphiles (IPA), in which the counterions have been removed. We have drawn up in this paper, an inventory of the different vesicular systems which have been described in the literature, insisting on the specific features associated with these two categories of systems. We have collected here especially, information concerning the phase behaviors, the microscopic composition of the vesicular particles, their structural and size determinations, the dynamic aspects (including the micelle–vesicle transition), the theoretical predictions from thermodynamic models and the entrapment of probe molecules. We discuss the potential of catanionic vesicles as delivery systems and we show that a full understanding of their entrapment/release properties will call for much more experimental work with well defined protocols. We also point out some unsolved questions concerning the role of the excess surfactant in the stabilization of the particles and the conditions required to obtain a favourable curvature of the surfactant film.

Most reactions involved in gene translation systems are ionic-dependent and may be explained in electrostatic terms. However, a number of observations of equilibria and rate processes making up the overall reactions clearly indicate that there is still an enormous gap between the rough picture of the mechanism of ionic regulation and the detailed behavior of reactions at the molecular level that hold the key to specific mechanisms. The present paper deals with possible osmotic contributions arising from the gel state of gene systems that are complementary to, and interdependent of, electrostatic contributions. This treatment, although still oversimplified, explains many previous observations by relating them to a general osmotic mechanism and suggests experimental approaches to studying the mechanisms of gene regulation in organelle-free and intact systems.