Showing papers on "Ionic liquid published in 1986"

Upon the structure of room temperature halogenoaluminate ionic liquids

Abstract: The X-ray structure of a monoclinic crystal of 1-methyl-3-ethylimidazolium iodide, [MeEtim]l, reveals the presence of discrete hydrogen-bonded ion-pairs [r{C(2)H ⋯ l–}= 0.293 nm]: the structural implications of the presence of hydrogen-bonding in ionic liquids based upon [MeEtim]X–AlX3(X = Cl or Br) mixtures are discussed.

Room-temperature ionic liquids as solvents for electronic absorption spectroscopy of halide complexes

Abstract: Solution studies of halide complexes of the transition metals, of general type [MXn]y− (X=Cl or Br), have been severely hampered by the existence of both solvation and solvolysis phenomena1. We demonstrate here that the use of room-temperature ionic liquids (often misleadingly referred to as molten salts) as solvents circumvents both of these problems, and permits the first reliable solution spectra to be recorded for these species; in some cases the spectra exhibit quite remarkable resolution.

Aluminum Bromide‐1‐Methyl‐3‐Ethylimidazolium Bromide Ionic Liquids I . Densities, Viscosities, Electrical Conductivities, and Phase Transitions

Abstract: The solid‐liquid phase diagram, experimental glass transition points, densities, viscosities, and electrical conductivities of the aluminum bromide‐1‐methyl‐3‐ethylimidazolium bromide ionic liquid are reported. Certain compositions of this two‐component molten salt are liquid at room temperature. Density, viscosity, and conductivity data were collected over the range of aluminum bromide mole fractions from ca. 0.35 to 0.75 and over the range of temperatures from ca. 25° to 100°C. Equations are presented that describe both the composition and temperature dependence of the densities and transport properties. Both the viscosities and the conductivities display the non‐Arrhenius temperature dependence typically associated with glass forming ionic liquids. Temperature‐dependent activation energies are derived for these transport processes by using the Vogel‐Tammann‐Fulcher equation.

Chloroaluminate equilibria in the aluminum chloride-1-methyl-3-ethylimidazolium chloride ionic liquid

Abstract: The stoichiometric equilibrium constant, , for the autosolvolysis reaction for the aluminum chloride‐1‐methyl‐3‐ethylimidazolium chloride ionic liquid was investigated as a function of temperature with a chloroaluminate concentration cell and aluminum electrodes. The values obtained at 40°, 50°, and 60°C for were , , and. The enthalpy change for the autosolvolysis reaction was found to be approximately 80 kJ mol−1 over this temperature range. A curve fitting method for determining the initial composition of this ionic liquid during a titration is also described.

Short range effective potentials for ionic fluids

Abstract: It is shown that the structure of a simple ionic liquid, potassium chloride, can be reproduced in computer simulations using short range effective pair (SHREP) potentials of a simple form. Aside from the balance between like and unlike particle interactions, the important parameters determining the structure are the depth e and the position r0 of the unlike particle pair energy minimum. The results demonstrate that the long range ordering characteristic of ionic liquids is not a consequence of the long range of Coulomb interactions. It is further shown that first order perturbation theory can be used accurately to calculate the thermodynamic properties of an ionic liquid from a corresponding reference liquid generated using a SHREP potential. These results can be generalized to explain deviations from the Reiss–Mayer–Katz corresponding states law for alkali halides and suggest an alternative scheme, effective depth reduction (EDR), based on values of e for the gas phase ion pairs.

Hydroquinone as a proton donor in ambient-temperature chloroaluminate ionic liquids: reaction with chloride ion

Abstract: On etudie la reaction de l'eau et de l'hydroquinone comme donneurs de protons soit dans chlorure de butyl-1 pyridinium-AlCl 3 soit dans chlorure de methyl-1 ethyl-3 imidazolium-AlCl 3 qui sont des liquides ioniques a temperature ambiante

Structure and thermodynamic properties of molten strontium chloride

Abstract: Self-consistent calculations of pair distribution functions and thermodynamic properties are presented for a pair potentials model of molten strontium chloride. The calculations extend to a strongly asymmetric ionic liquid, an earlier assessment of bridge diagrams in a modified hypernetted chain approach to the liquid structure of alkali halides. Good agreement is found with computer simulation data obtained by de Leeuw (1978) with the same set of pair potentials, showing that the present approach incorporates genuine general features of liquid structure theory for multicomponent liquids with strong relative ordering of the component species. It is further shown that the strong correlations between the divalent cations, both in the model and in real molten strontium chloride, can be approximately reproduced on the basis of a simple one-component-plasma model, provided that dielectric screening is allowed for in the real liquid. This allows the authors tentatively to attribute the significant level of disagreement between a pair potentials model of this liquid and the neutron diffraction data of McGreevy and Mitchell (1982) to many-body distortions of the electronic shells of the ions.

Chapter 10 – Ionic Liquids

Abstract: Chapter 10 deals with the statics and dynamics of systems of charged particles: ionic liquids (electrolyte solutions and molten salts) and liquid metals. The key feature of such systems is the infinite range of the bare electrostatic interaction, which leads to Debye screening and charge ordering effects; screening can be quantified by macroscopic (longwavelength) considerations. Integral equation approximations give reasonable results for the pair structure and thermodynamics of ionic liquids. Frequency-dependent electric response is studied by use of extension of the techniques introduced in Chapter 8 and density functional theory is used to characterise the structure of electric double-layers near charged surfaces. The structure and dynamics of liquid metals, which are two-component systems of classical cations and a quantum fluid of degenerate conduction electrons, are briefly reviewed.

Optical parts having variable refracting power

Abstract: PURPOSE:To change the refracting power of the optical parts by constituting the optical parts which encloses an ionic liquid uniformly dispersed the optical transparent charging particles in the optical transparent liquid into the optical transparent vessel, and by impressing a voltage to the electrode provided on a part of the vessel to change the refractive index of the ionic liquid. CONSTITUTION:The transparent electrocharged particle 5 is dissolved to the liquid 4 composed of an aqueous ion of Tl NO 3 (thallium nitrate ion). The optical parts is constituted by enclosing an ionic liquid so as to fill up the ionic liquid in a hollow part 2a of the vessel 2 followed by enclosing it with the transparent cover 1. When the voltage coming from the electric source 6 is impressed to the electrode 3 by setting 'on' the switch 7, each ions are attracted to the electrode which has a different polarity for the ion whereby the ion contg. in the ionic liquid in the center of the titled parts is removed or reduced. Therefore, the refractive index in the center of the titled parts reduces, thereby reducing the refracting power of the titled parts, when the switch is set to 'on'.

Studies of Antimony(III) in Ambient-Temperature Ionic Liquids.

Abstract: On etudie le comportement de Sb(III) dans les masses fondues AlCl 3 -RCl, par voltammetrie cyclique. (R + =methyl-1 ethyl-3 imidazolium). Presence de SbCl 2 + dans les melanges fondus