Phase Equilibria and Ionic Solvation in the Lithium Tetrafluoroborate–Dimethylsulfoxide System

The phase diagram and electrical conductivity isotherms for the lithium tetrafluoroborate (LiBF4)–dimethylsulfoxide (DMSO) system and Raman spectra of DMSO and the LiBF4–DMSO solution were studied. Spectroscopic signatures of a H-bond between DMSO and BF4− ions were found. The bonds of Li+ ions to the solvent were stronger than the bonds in DMSO dimers because formation of the solvate destroyed dimeric DMSO molecules. The τω values for DMSO molecules in the Li+-ion solvate shell of the LiBF4–DMSO system were similar to those for associated solvent molecules.