Solvation interactions in solutions of lithium hexafluoroarsenate in propylene carbonate

On the basis of the dissolution heat in propylene carbonate (PC) measured at 298.15 K, and the electroconductivity, ultrasound propagation velocity, and solution density and viscosity measured at 283.15-313.15 K, the LiAsF6 solvation in PC is discussed. The LiAsF6 solvation enthalpy and its ionic components are determined. It is shown that the donor-acceptor interaction between Li+ and the oxygen atom of the carbonyl group of PC makes the main contribution to the enthalpy. The effects of the concentration and temperature on the molar electroconductivity, viscosity, apparent molar volume, and electrolyte compressibility are analyzed, and thermodynamic parameters of the activation of viscous flow and electroconductivity are considered. Using the Onori approach, parameters of solvation complexes in solution, such as solvation numbers, volumes, compressibilities, and their dependences on the concentration are determined. A considerable solvent compressibility is noted in the inner sphere of the complex.