title: Ion pair formation in [bmim]I ionic liquids.
abstract: Ion pair formation between [bmim](+) and iodide has been studied in acetonitrile solutions and in ionic liquids. In solution, absorption spectra change remarkably with concentration, indicating the formation of charge transfer (CT) complexes. The shape of CT complex spectra can be explained by ab initio molecular orbital calculations. On the basis of the results from the solution and spectroscopic absorption measurements, we confirmed that CT complexes were formed in neat [bmim]I ionic liquid. High stability of the CT complex is demonstrated by the temperature dependence of near-IR absorption measurements.
authors.affiliation: National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan. r-katoh@aist.go.jp
authors.forename: Ryuzi
authors.initials: R
authors.lastname: Katoh
authors.forename: Mikiya
authors.initials: M
authors.lastname: Hara
authors.forename: Seiji
authors.initials: S
authors.lastname: Tsuzuki