1-butyl-3-methylimidazolium-chloride and ferric-chloride

We synthesized a series of FeCl(3)/[C(4)mim]Cl (iron(III) chloride with 1-butyl-3-methylimidazolium chloride) ionic liquids. The temperature dependence of the Raman spectra of the FeCl(3)/[C(4)mim]Cl ionic liquids was measured for the first time to analyze their ionic species. In addition, the infrared spectra, thermodynamic properties, and freeze-fracture transmission electron microscopy were combined together with the Raman spectra to reveal the microscopic information of the FeCl(3)/[C(4)mim]Cl ionic liquids. When the mole ratio of FeCl(3)/[C(4)mim]Cl is less than 1, the Raman scattering identifies the presence of [FeCl(4)](-) in the ionic liquid. When FeCl(3) is in excess, [Fe(2)Cl(7)](-) begins to appear. Besides, we found that the relative intensity of the two symmetry vibrations of [Fe(2)Cl(7)](-) is changing as the temperature is varied. The strength of the interionic interactions in FeCl(3)/[C(4)mim]Cl ionic liquids follows the order 1/1.5 > 1.5/1 > 1/1 due to the formation of [FeCl(4)](-) and [Fe(2)Cl(7)](-). The nanostructures in FeCl(3)/[C(4)mim]Cl ionic liquids were observed for the first time by using biological imaging. The sizes of the local domains are found to be tens of nanometers.

Topics: Chlorides; Ferric Compounds; Imidazoles; Ionic Liquids; Ions; Molecular Structure; Nanostructures; Particle Size; Surface Properties; Thermodynamics

The radiation stability of the ionic liquid 1-butyl-3-methylimidazolium chloride ([Bmim]Cl) was investigated after (60)Co γ irradiation at doses up to 600 kGy. Thermal and spectroscopic analysis revealed the formation of a small quantity of radiolytic products and an evident change in the physicochemical properties of the ionic liquid. The presence of anionic FeCl(4)(-) (up to 5 mol%), as measured by UV-vis absorption, differential scanning calorimetry, and Raman spectroscopy, significantly improved the radiation resistance of [Bmim]Cl. The increased resistance may be due to the capture of a solvated electron (e(solv)(-)) by FeCl(4)(-) to form FeCl(4)(2-) and results in the radiation protection of the organic cation. The radiation yield of the reductive species (Fe(II)) was estimated to be 0.217 ± 0.010 µmol/J (2.09 ± 0.10/100 eV), which is considered close to the radiation yield of the solvated electrons of [Bmim]Cl.

Topics: Calorimetry, Differential Scanning; Chlorides; Color; Dose-Response Relationship, Radiation; Electrons; Ferric Compounds; Gamma Rays; Imidazoles; Ionic Liquids; Solvents; Spectrum Analysis; Temperature