Showing papers on "Ionic liquid published in 1980"
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01 Nov 1980
TL;DR: In this paper, the effect of pressure on electrical conductivity at ambient temperatures and ambient temperatures was investigated. But the authors focused on the effect on the conductivity of dilute electrolyte solutions.
Abstract: 1. Introduction and Definitions.- 1.1. Introduction.- 1.2. Electrical Conductivity.- 1.3. Diffusion and Viscosity.- 1.3.1. The Diffusion Coefficient.- 1.3.2. Viscosity.- 1.4. The Stokes-Einstein and Nernst-Einstein Relations.- 1.4.1. The Stokes-Einstein Relation.- 1.4.2. The Nernst-Einstein Relation.- 1.4.3. The Walden Product.- 2. Ionic Conductivity in Dilute Electrolyte Solutions.- 2.1. Concentration Dependence of Conductivity of Dilute Electrolyte Solutions-Introduction.- 2.1.1. Derivation of the Conductance Equations.- 2.1.2. The Relaxation Effect.- 2.1.3. The Electrophoretic Effect.- 2.1.4. Conductivity Equations for Nonassociated Electrolytes.- 2.1.5. Conductivity Equations for Associated Electrolytes.- 2.1.6. Test of the Conductivity Equation.- 2.2. The Concentration Dependence of Conductivity at High Pressure and Moderate Temperatures.- 2.3. The Concentration Dependence of Conductivity at High Pressure and Temperature.- 2.4. The Effect of Pressure on Electrical Conductivity at Ambient Temperatures.- 2.4.1. Hydrogen-Bonded Solvents.- 2.4.2. Neutral Solvents.- 2.5. The Effect of Pressure on the Conductivity of Electrolyte Solutions at High Temperatures and Pressures.- 2.6. Excess H+ and OH- Mobility in Aqueous Solutions.- 2.7. The Limiting Ionic Conductivity of Ions in Solution.- 2.7.1. The Molecular Hydrodynamic Approach.- 2.7.2. The Transition State Theory.- 3. Ionic Conductivity in Low-Temperature Molten Salts and Concentrated Solutions.- 3.1. The Transition from Dilute Solutions to Molten Salts.- 3.2. Composition Dependence of Conductance in Concentrated Solutions and Low-Temperature Molten Salts.- 3.2.1. The Dilute Solution Approach.- 3.2.2. The Molten Salt Approach.- 3.3. Temperature and Pressure Dependence of Conductance in Concentrated Solutions and Low-Temperature Molten Salts.- 3.4. Electrical Relaxation in Glass-Forming Molten Salts.- 4. Electrical Conductivity in Ionic Liquids at High Temperatures.- 4.1. The Temperature and Pressure Dependence of Electrical Conductivity in Ionic Liquids.- 4.2. Theories for Electrical Conductivity in Ionic Melts.- 4.2.1. Transition State Theory.- 4.2.2. The Hole Model of Liquids.- 4.2.3. The Theory of Significant Liquid Structures.- 4.2.4. The Kirkwood-Rice-Allnatt Kinetic Theory of Electrical Conductance.- 4.2.5. The "Free Ion" Theory of Conductance of Barton and Speedy.- 4.2.6. Other Theories.- 5. Ionic Conductivity in Molecular Liquids and Partially Ionized Molten Salts.- 5.1. Introduction.- 5.2. The Temperature and Pressure Dependence of Conductivity.- 5.3. Conclusions.- 6. Electrical Conductivity in Liquids of Geological and Industrial Interest.- 6.1. Geological Liquids.- 6.1.1. Seawater.- 6.1.2. Geothermal Waters.- 6.1.3. Silicate Melts and Magmas.- 6.2. Industrial Electrolytes.- 6.2.1. Aqueous Industrial Electrolytes.- 6.2.2. Nonaqueous Electrolyte Solutions.- 6.2.3. Molten Salt Electrolytes.- References.
114 citations
TL;DR: In this paper, the spatial correlations between the ions themselves and between the ion and water molecules are compared between theory and experiment, and the results of these comparisons are discussed and areas in which the theory is in urgent need of revision.
Abstract: Two types of ionic liquids are considered: molten salts and aqueous solutions of strong electrolytes. It is shown that in both cases, modern theoretical methods are capable of making definite predictions about the spatial correlations between the ions themselves and between the ions and water molecules. It is further shown that the technique of neutron diffraction as applied to isotopically enriched samples allows, for the first time, detailed comparisons to be made between theory and experiment. The results of these comparisons are discussed and areas in which the theory is in urgent need of revision are identified.
113 citations
TL;DR: In this paper, NMR results are reported for liquid Cs-Au alloys ranging from pure Cs to 18% excess Au in the ionic liquid compound CsAu.
Abstract: $^{133}\mathrm{Cs}$ NMR results are reported for liquid Cs-Au alloys ranging from pure Cs to 18% excess Au in the ionic liquid compound CsAu. As one approaches CsAu from the Cs-rich side, a rapid drop in the Knight shift is observed, accompanied by a sharp peak in the nuclear relaxation rate at about 5% excess Cs in CsAu. Analysis of the static and dynamic hyperfine fields shows that the conduction electrons abruptly localize, probably as $F$- center analogs, when the concentration of excess Cs falls below about 7%.
38 citations
33 citations
TL;DR: In this paper, the existence of semiconducting behavior in liquid systems is mostly related to a continuous transition from a metallic to a semiconducting state when a thermodynamic variable such as temperature, density or concentration is changed.
Abstract: Numerous liquid systems have electrical properties which resemble those of crystalline and amorphous semiconductors. The existence of “semiconducting” behavior in these liquids is mostly related to a continuous transition from a metallic to a “semiconducting” state when a thermodynamic variable such as temperature, density or concentration is changed. Changes in the nature of the chemical interaction and the associated changes in the structure of the liquid are of fundamental importance for the transition to a “semiconducting” state. This will be demonstrated for the ionic liquid CsAu, for covalent liquid selenium, and for expanded liquid metals.
24 citations
TL;DR: In this paper, the Debye Huckel screening length in the ionic melt is a fixed fraction, for the whole family of alkali halides, of the molecular equilibrium spacing, and a corresponding states argument is used to make predictions about the critical point.
Abstract: Ionic liquids, on boiling, are expected to be in equilibrium with molecular vapours. It is to be anticipated that the temperature range of the ionic liquid phase is extensive and comparable with the stability range of the solid. This is confirmed by available data. Boiling at low pressure is found from the data to occur when the Debye Huckel screening length in the ionic melt is a fixed fraction, for the whole family of alkali halides, of the molecular equilibrium spacing. Starting from this regularity, a corresponding states argument is used to make predictions about the critical point. Melting of a solid ionic phase into a molecular phase is a more system specific phenomenon. Characteristics favourable for such phase transitions are: (i) Large valence difference between cation and anion. (ii) Highly polarizable valence shells on the ions, such as arise with rather weakly bound d-electrons on the cation. To exemplify these points, the cases of the aluminium halides and the mercury halides are co...
15 citations
TL;DR: In this paper, the synthesis of several analogues of the chloralformamide fungicides is reported, which include N-methyl-N-(2, 2,2,2-trichloro- 1-arylaminoethyl)formamides and related alkoxyethyl and aryloxyethyl derivatives, and the results of their evaluation as fungicides are reported.
Abstract: The synthesis of several analogues of the chloralformamide fungicides is reported. The compounds, which comprise N-methyl-N-(2,2,2-trichloro- 1-arylaminoethyl)formamides and related alkoxyethyl and aryloxyethyl derivatives, exist at room temperature as two isomers due to restricted rotation about the C-N amide bond. The results of their evaluation as fungicides are reported.
14 citations
TL;DR: In this paper, the methoxide anion (produced from methyl nitrite) reacts with neutral ketones (M) to form nondecomposing (M-H+)- ions.
Abstract: The methoxide anion (produced from methyl nitrite) reacts with neutral ketones (M) to form non-decomposing(M-H+)- ions. The (M-H+)- ions are ambident species and they undergo a number of ion-molecule reactions, including (i) characteristic reactions through the carbanion centre with methyl nitrite, and (ii) for acetone, the formation of an [M +(M- H+)]- ion. In several cases peaks due to collision-stabilized (M+MeO-) ions are observed (e.g. MeO-/acetone), but they are not detected for the majority of cases studied.
11 citations
TL;DR: In this article, a reaction between poly(pyrazolyl)borate anions with HAuCl4 has been shown to give the complexes AuCl2[(pz)2BPh2], AuCl 2BH, AuCl 4BH and P(OMe)3.
Abstract: Reactions of poly(pyrazolyl)borate anions with HAuCl4 have given the complexes AuCl2[(pz)2BPh2], AuCl2[(pz)3BH], AuCl2[(Me2pz)3BH] and AuCl2[(pz)4B] (pz = pyrazolyl, C3H3N2; Me2pz = 3,5-dimethylpyrazolyl); AuCl2[(Me2pz)3BH] decomposes rather easily to form [AuCl2(Me2pz)]3, while Au(pz)[P(OMe)3] was obtained from a reaction between AuCl2[(pz)4B] and P(OMe)3.
8 citations
TL;DR: In this paper, the substitution of the aqua[tris{2-(dimethylamino)ethyl}amine]copper(II) ion by cyanate, chloride and bromide ions has been studied in aqueous solution by static and stopped-flow spectrophoto-metric techniques.
Abstract: The substitution of the aqua[tris{2-(dimethylamino)ethyl}amine]copper(II) ion by cyanate, chloride and bromide ions has been studied in aqueous solution by static and stopped-flow spectrophoto-metric techniques. This process is unusually slow for ligand substitution at a copper(II) centre and appears to proceed through an interchange mechanism in which the copper(II)-aqua ligand bond makes a major contribution to the transition state energetics.
8 citations
TL;DR: Excess volumes for binary mixtures of 1-chlorobutane with hexane, heptane, octane and nonane were measured dilatometrically at 303.15 K as mentioned in this paper.
Abstract: Excess volumes for binary mixtures of 1-chlorobutane with hexane, heptane, octane and nonane were measured dilatometrically at 303.15 K. Excess volumes are positive over the entire range of composition in the four mixtures. Further, it is observed that increase in chain length increases the magnitude of the excess function.
TL;DR: In this paper, the trisoxalato)chromate(III) anion has been followed in benzene solutions of dodecylammonium propionate or octylammonium tetradecanoate containing solubilized water at 298 K.
Abstract: The reactivity of the tris(oxalato)chromate(III) anion has been followed in benzene solutions of dodecylammonium propionate or octylammonium tetradecanoate containing solubilized water at 298 K. The reaction rate against detergent concentration profiles are complex.
TL;DR: In this article, three series of solid solutions, K2[(Pt/M)Cl6] (M = Re, Os, Ir), have been prepared and their infrared, structural and magnetic properties investigated.
Abstract: Three series of solid solutions, K2[(Pt/M)Cl6] (M = Re, Os, Ir), have been prepared and their infrared, structural and magnetic properties investigated. The variation in the crystal cubic cell dimension correlates with composition of the solid solutions. Correlations of the magnetic and vibrational data with the cell dimensions of the solids are not statistically significant.
TL;DR: Surface tension measurement of the critical micelle concentration, CMC, of cationic hexadecyltrimethylammonium bromide, ctab, shows a significant increase on addition of very small amounts of 4- nitroacetanilide.
Abstract: Surface tension measurement of the critical micelle concentration, CMC, of cationic hexadecyltrimethylammonium bromide, ctab, shows a significant increase on addition of very small amounts of 4- nitroacetanilide. At concentrations above the CMC, ctab catalyses the hydrolysis of 4-nitroacetanilide.The micellar catalysis is inhibited by added salts, especially those of arenesulfonates and bulky carboxylate ions. The kinetics have been analysed in terms of competitive binding of the substrate and the inhibitor to the micelle.
TL;DR: In this paper, an applied pressure of 2000 bars (1 bar = 105 Pa ≡ 0.9869 atm) was found to double the rate of photodimerization of methyl 3-methoxy-2-naphthoate in solution in toluene and in methanol at 20°C.
Abstract: An applied pressure of 2000 bars (1 bar = 105 Pa ≡ 0.9869 atm) has been found to double the rate of photodimerization of methyl 3-methoxy-2- naphthoate in solution in toluene and in methanol at 20°C. The acceleration corresponds to an average activation volume between 1 and 2000 bars of ΔV‡av ≈ -10 cm3 mol-1, and is much less than the known acceleration, under similar conditions, of analogous thermal reactions.
TL;DR: In this paper, the reactions of 11 inorganic anions added as their sodium or potassium salts to molten sodium-potassium hydrogen sulfate eutectic were studied and their stoichiometries elucidated.
Abstract: The reactions of 11 inorganic anions added as their sodium or potassium salts to molten sodium-potassium hydrogen sulfate eutectic were studied and their stoichiometries elucidated. It was found that Na2CO3, NaNO2, KNO3, Na2SO3 and Na2S2O3 reacted with the melt to form water and CO2, NO+NO2, NO2+O2, SO2, S6+SO2 respectively. NaCl, KBr produced HCl and HBr while KI reaction products consisted of I2, SO2 and H2O; K2CrO4 and K2Cr2O7 were converted into H2CrO4 and H2Cr2O7 respectively. These acids decomposed to H2O, O2 and Cr2O3 which reacted further with the melt to produce H2O and Cr2(SO4)2,H2O. K2S2O8 was found to decompose thermally to O2 and K2S2O7 without reacting with the melt.
TL;DR: Results in solutions of both constant and nonconstant ionic strength confirm that the ionic environment of the solvent water is a determining factor in the magnitude of the catalytic effect.
Abstract: The kinetics of racemization of Λ-bis(oxalato)(1,10-phenanthroline)chromate(III) anion in solutions of CuII salts, at an ionic strength of 2, fit the expression, rate = (k1+k2[CuIIF])[complex] where [CuIIF] is the concentration of 'free' copper(II) ions in solution as calculated from ion pair formation constants for copper(II) salts. Results in solutions of both constant and nonconstant ionic strength confirm that the ionic environment of the solvent water is a determining factor in the magnitude of the catalytic effect. Thus a divalent sulfate medium is more effective than any of the monovalent perchlorate, nitrate or chloride salts.
01 Jan 1980
TL;DR: In this paper, the authors discuss ionic conductivity in ionized molten salts at temperatures well above T 0 and show that at very high temperatures and low densities the fate of most ionic liquids is to become molecular, with a consequent drop in conductivity.
Abstract: This chapter will be concerned with the discussion of ionic conductivity in ionized molten salts at temperatures well above T0. At very high temperatures and low densities the fate of most ionic liquids is to become molecular, with a consequent drop in conductivity. The discussion of this phenomenon and of melts that are extensively molecular even at their melting points will be delayed to the next chapter. An ionic melt possesses a high number of charge carriers per unit volume, and if these are mobile the conductivity will be high. Klemm has defined an ionic melt as one whose conductivity K >10-3 S cm-1. This definition is quite arbitrary, but it does seem to include most melts that are regarded as being predominantly ionized. A notable exception, for example, is the tetraalkyl ammonium tetrafluoroborate salts.
TL;DR: The ionic potential is considered as a parameter representative of chromatographic behaviour in ionic compounds and a correlation is proposed between the RM value and the ionic Potential of the cation and the anion respectively.
Abstract: The ionic potential is considered as a parameter representative of chromatographic behaviour in ionic compounds and a correlation is proposed between the RM value and the ionic potential of the cation and the anion respectively. For the alkaline earth chlorides, the discontinuity in the graph of-RM versus ionic potential of the cation, is explained beyond the change of ionic character in these compounds. For the barium halides, the change in the order of RF is estimated from the polarizability of the anion.
TL;DR: In this article, it was shown that melting points and boiling points of alkali fluorides, chlorides, alkali bromides and alkali iodides form parabolas as a function of Coulomb energy x =q2/(rc+ra).
Abstract: Melting points and boiling points of alkali fluorides, alkali chlorides, alkali bromides and alkali iodides, have been found to form parabolas as a function of Coulomb energy x=q2/(rc+ra). Melting points versus x for oxides of cations with rare gas-type outer electronic shells have been found to behave similarly. A primary explanation of such parabolic behaviors of melting points versus x is given and a quartic behaviors of enthalpy of fusion versus x for ionic substances which is caused by multipole interactions in ionic liquids is demonstrated.
TL;DR: In this paper, the existence of semiconducting behavior in liquid systems is mostly related to a continuous transition from a metallic to a semiconducting state when a thermodynamic variable such as temperature, density or concentration is changed.
Abstract: Numerous liquid systems have electrical properties which resemble those of crystalline and amorphous semiconductors. The existence of “semiconducting” behavior in these liquids is mostly related to a continuous transition from a metallic to a “semiconducting” state when a thermodynamic variable such as temperature, density or concentration is changed. Changes in the nature of the chemical interaction and the associated changes in the structure of the liquid are of fundamental importance for the transition to a “semiconducting” state. This will be demonstrated for the ionic liquid CsAu, for covalent liquid selenium, and for expanded liquid metals.
01 Jan 1980