title: Microscopic solvation environments in a prototype room-temperature ionic liquid as elucidated by resonance Raman spectroscopy of iodine and bromine.
abstract: Microscopic solvation environments in a prototype ionic liquid, bmimTf2N; 1-butyl-3-methyl-imidazolium-bis(trifluoromethanesulfonyl)imide, have been studied with the use of halides, X2and Xn-(X=I, Br; n=3,5), as molecular probes. Resonance Raman spectroscopy has been used to detect these halogen species existing in bmimTf2N as well as in reference solvents including heptane, cyclohexane, KX/H2O and benzene. In heptane and cyclohexane, only free X2species are detected. In KX/H2O, only Xn-and, in benzene, only benzene-X2complexes are detected. On the contrary, free X2and Xn-are concomitantly detected in bmimTf2N, indicating that there are two distinct solvation environments in bmimTf2N, non-polar environments that solvate free X2and polar environments that stabilize Xn-. These two distinct solvation environments are most likely to arise from microscopic structural heterogeneity of ionic liquids.
authors.affiliation: Department of Chemistry, Centre for Advanced Studies, Institute of Science, Banaras Hindu University, Varanasi 221005, India.
authors.forename: Satyen
authors.initials: S
authors.lastname: Saha
authors.affiliation: Institute of Molecular Science, National Chiao Tung University, 1001 Ta Hsueh Road, Hsinchu 300, Taiwan.
authors.forename: Hajime
authors.initials: H
authors.lastname: Okajima
authors.affiliation: Department of Chemistry, School of Science, The University of Tokyo, Hongo 7-3-1 Bunkyo-ku, Tokyo, 113-0033, Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Homma
authors.affiliation: Institute of Molecular Science, National Chiao Tung University, 1001 Ta Hsueh Road, Hsinchu 300, Taiwan; Department of Chemistry, School of Science, The University of Tokyo, Hongo 7-3-1 Bunkyo-ku, Tokyo, 113-0033, Japan. Electronic address: hhama@chem.s.u-tokyo.ac.jp.
authors.forename: Hiro-O
authors.initials: HO
authors.lastname: Hamaguchi
keywords: Iodine/bromine; Ionic liquid; Microscopic heterogeneity; Raman spectroscopy; Solvation environment