The structure and solvation of ions are studied from different aspects using various kinetic, spectroscopic and thermodynamic techniques. The solvation of a wide range of ions, both simple and complex, is investigated by calculation of sets of single-ion transfer chemical potentials for a series of binary aqueous solvent mixtures. Observed trends are discussed in terms of the effects on ion solvation of solute and solvent structure and solute-solvent interactions. Structure, solvation and also reactivity of sane low- spin iron (II) di-imine complexes containing unsymmetrical Schiff base ligands are investigated using a variety of techniques. The occurrence of diastereoisomerism in complexes of this type is probed using complementary techniques which highlight different aspects of this phenomenon. Thus, the differing reactivities of, and the differing spatial orientations in, possible diastereoisomeric forms are utilized in detecting diastereoisomers by kinetic and 1H nmr spectroscopic methods respectively. In addition, for complexes of this type, links between structure, solvation and reactivity are investigated using kinetic data, solubility data, ultraviolet/visible absorption spectra and 1H nmr spectra obtained for the complex species.