title: Solvatochromic studies of ionic liquid/organic mixtures.
abstract: Room-temperature ionic liquids (ILs) have potential for many different applications, including catalysis and synthesis. Organics are often present during IL applications; therefore, a more fundamental understanding of the interactions between IL and organics is necessary. A systematic study of the effects of organic cosolvents, cations, and anions on the solvent strength of IL/organic mixtures will allow for a greater understanding and potential for tuning of ILs for specific purposes. Solvent strength is commonly quantified using spectroscopic probes. We report the solvent strength of IL/organic mixtures using Reichardt's dyes 30 and 33, Kamlet-Taft parameters, and phenol blue. The results show that the polarity of ILs is largely unaffected by the organic cosolvent; that is, the probes are preferentially solvated by the ILs. However, more specific solvation forces, such as hydrogen bonding, can be influenced indirectly by the strength of the anion/cation interaction, giving counterintuitive results.
authors.affiliation: Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana 46556, USA.
authors.forename: Berlyn R
authors.initials: BR
authors.lastname: Mellein
authors.forename: Sudhir N V K
authors.initials: SN
authors.lastname: Aki
authors.forename: Rebecca L
authors.initials: RL
authors.lastname: Ladewski
authors.forename: Joan F
authors.initials: JF
authors.lastname: Brennecke