Solvation vs. Surface Charge Transfer: An Interfacial Chemistry Game Drives Cation Motion

Electrolyte structure and ion solvation dynamics determine ionic conductivities, and ion (de)solvation processes dominate interfacial chemistry and electrodeposition barriers. We elucidate electrolyte effects facilitating or impeding Li+ diffusion and deposition,...

Hydrogen-bonded host–guest systems are stable in ionic liquids

We show that H-bonded host–guest systems associate in ionic liquids (ILs), pure salts with melting point below room temperature, in which dipole–dipole electrostatic interactions should be negligible in comparison with dipole-charge interactions. Binding constants (Ka) obtained from titrations of four H-bonded host–guest systems in two organic solvents and two ionic liquids yield smaller yet comparable Ka values in ionic liquids than in organic solvents. We also detect the association event using force spectroscopy, which confirms that the binding is not solely due to (de)solvation processes. Our results indicate that classic H-bonded host–guest supramolecular chemistry takes place in ILs. This implies that strong H-bonds are only moderately affected by surroundings composed entirely of charges, which can be interpreted as an indication that the balance of Coulombic to covalent forces in strong H-bonds is not tipped towards the former.

Testing the flow-through capillary for the study of re-solvation processes in pharmaceutical compounds

This paper describes a new flow-through capillary sample holder that allows the in situ study of re-solvation processes. The holder can be aligned to the goniometer's center using two perpendicular micrometric tables that move in y and z directions. The re-solvation of two ibrutinib solvates of anisole and fluorobenzene was tested using the holder to show the practical application of this technique.

Molecular modeling analyses for the effect of solvents on amino acids

Influence of solvation with various solvents is a vital issue for several applications of amino acids. Considering the impact of solvents and many other factors is an important point of research to get much more accurate data on their behavior. Hence, molecular modeling calculations were conducted for some amino acids in both cases; gaseous state and under the effect of several solvents; DMSO, acetonitrile, nitromethane, and methanol. DFT was utilized at B3LYP theoretical level and 6-31G(d,p) as a basis set. Geometrical parameters of both amino and carboxyl terminals were studied. Resulting data ascertain that various solvation processes impact the interested parameters that have to be considered for further applications.

Negative Redox Potential Shift in Fire-Retardant Electrolytes and Consequences for High-Energy Hybrid Batteries

Fire-retardant electrolyte chemistries have attracted great attention given their potential to solve the grand challenges of alkali-ion batteries : safety, use of metallic anodes and anodic stability. Whereas extensive analysis and correlations are drawn to explain their unusual electrochemical behaviour, one essential property, their effects on redox potentials of battery components (redox potential shift) pervasively lack a strict description and quantification. Here we show that the strong solvation of lithium cations by organic phosphates, the widely used flame-retardant constituents, induces a negative redox potential shift by as much as 500mV. We demonstrate that the redox potential shift is characteristic of Li-cation (de)-solvation processes whereas negligible for other processes. This has important consequences for high energy hybrid battery concepts such as high voltage dual-ion graphite or organic batteries. These findings also shine a different light on the enhanced anodic stability of these non-conventional battery electrolyte formulations.

Negative Redox Potential Shift in Fire-Retardant Electrolytes and Consequences for High-Energy Hybrid Batteries

Fire-retardant electrolyte chemistries have attracted great attention given their potential to solve the grand challenges of alkali-ion batteries : safety, use of metallic anodes and anodic stability. Whereas extensive analysis and correlations are drawn to explain their unusual electrochemical behaviour, one essential property, their effects on redox potentials of battery components (redox potential shift) pervasively lack a strict description and quantification. Here we show that the strong solvation of lithium cations by organic phosphates, the widely used flame-retardant constituents, induces a negative redox potential shift by as much as 500mV. We demonstrate that the redox potential shift is characteristic of Li-cation (de)-solvation processes whereas negligible for other processes. This has important consequences for high energy hybrid battery concepts such as high voltage dual-ion graphite or organic batteries. These findings also shine a different light on the enhanced anodic stability of these non-conventional battery electrolyte formulations.

Impact of solvation on the geometrical parameters of some amino acids

The impact of the utilized solvent is of an important concern. Eliminating the effect of solvents and other factors is a crucial point in order to get more accurate results. Therefore, density functional theory DFT calculations at B3LYP/ 6-31G(d,p) level were carried out for a number of amino acids in the gaseous state and also under the effect of various solvation processes using different solvents; DMSO, acetonitrile (AN), nitromethane (NM) and methanol (Meth). Geometrical parameters of both N and C terminals were investigated. Results demonstrate that different solvation processes affect the studied parameters that should be considered for future applications.