DescriptionPhysical chemistry of ionic liquids (ILs) is investigated. First, ILs are used as solvents for photoinduced intramolecular electron-transfer (ET) reactions of a donor-bridge- acceptor compound. The solvation dynamic effect of the ILs on the intramolecular ET is compared with that in neutral solvents. The ET rates in ionic liquids are slower and very broadly distributed compared to narrowly distributed rates in the neutral solvents. In addition, the reaction kinetics in the ILs are dynamically heterogeneous. Dynamic heterogeneity, however, is not a unique quality to ILs; glass systems also show such behavior. To determine the degree to which this dynamic heterogeneity arises from, we examine the structural heterogeneity of ILs. We study the local structure of ILs using 2D NMR spectroscopy on the set of four homologous ILs. The results suggest intermolecular interactions between hydrogen atoms on the cation ether- chains and the fluorine atoms on the anions - such interaction is not found for the octyl-chained ILs. Lastly, physical and chemical properties of novel paramagnetic ionic liquids/solids are characterized. The crystal structures of these ionic compounds are solved and the magnetic properties are reported.