Abstract/Summary

Ions in solution are ubiquitous within a broad range of chemical applications, e.g., batteries, catalysis, renewable energy production, and aerosols. The physico-chemical properties of each component within solution enables their function within each application, which are in turn determined by their electronic structure. It is well known that solvent-solute interactions influence the electronic structure of each component within solution. However, knowledge of the governing factors, which control how the contributing atomic and molecular orbital energies of solvent and solute species are influenced for liquid phase ions, is heavily lacking. This fact is especially true for solvents other than H2O. X-ray spectroscopic techniques provide the means to probe the electronic structure of every component in solution. Experiments yield information on how the electronic structure of components in solution are affected upon different chemical changes. The extent and reasoning as to the influence of solvent identity on the anionic electronic structure was explored (Chapter 3). A strong correlation was found between the anionic molecular orbital energies and solvent Lewis acidity. All anionic molecular orbital energies were affected equally with varying solvent identity; hence, observed solvation effects were stated as non-specific in nature. For all anion identities measured, destabilisation of the anionic electronic structure upon increasing electrolyte concentration was observed (Chapter 4). Although anion identity was found to influence the extent of anionic destabilisation, the effect of varying anion identity on solvent molecular orbitals was shown to be insignificant. Varying the concentration of ions in solution was shown to significantly influence the electronic structure of each component (Chapter 5). Both anionic and solvent molecular orbitals were found to decrease in energetic stability with increasing electrolyte concentration. Moreover, a strong linear relationship between core and valence state energies was obtained, once again suggesting that non-specific solvation effects dominate. The effect of solvent identity on the cationic electronic structure was determined (Chapter 6). Strongly coordinating cations were found to be equally as Lewis acidic within both, aqueous, and organic solvents, in contrast to weakly coordinating cationic species.