title: Ionic liquids based on FeCl(3) and FeCl(2). Raman scattering and ab initio calculations.
abstract: We have prepared ionic liquids by mixing either iron(II) chloride or iron(III) chloride with 1-butyl-3-methylimidazolium chloride (BMIC). Iron(II) chloride forms ionic liquids from a mole ratio of 1 FeCl(2)/3 BMIC to almost 1 FeCl(2)/1 BMIC. Both Raman scattering and ab initio calculations indicate that FeCl(4)(2-) is the predominant iron-containing species in these liquids. Iron(III) chloride forms ionic liquids from a mole ratio of 1 FeCl(3)/1.9 BMIC to 1.7 FeCl(3)/1 BMIC. When BMIC is in excess, Raman scattering indicates the presence of FeCl(4-). When FeCl(3) is in excess, Fe(2)Cl(7-) begins to appear and the amount of Fe(2)Cl(7-) increases with increasing amounts of FeCl(3). Ionic liquids were also prepared from a mixture of FeCl(2) and FeCl(3) and are discussed. Finally, we have used both Hartree-Fock and density functional theory methods to compute the optimized structures and vibrational spectra for these species. An analysis of the results using an all-electron basis set, 6-31G, as well as two different effective core potential basis sets, LANL2DZ and CEP-31G is presented.
authors.affiliation: Division of Science, Truman State University, 100 East Normal, Kirksville, Missouri 63501, USA.
authors.forename: M S
authors.initials: MS
authors.lastname: Sitze
authors.forename: E R
authors.initials: ER
authors.lastname: Schreiter
authors.forename: E V
authors.initials: EV
authors.lastname: Patterson
authors.forename: R G
authors.initials: RG
authors.lastname: Freeman