Showing papers on "Ionic liquid published in 1991"
TL;DR: It is shown that SH surface waves in particular and acoustic waves in general can be used to perform microanalysis of dilute ionic solutions, detecting conductivity, dielectric constant, and relaxation frequency.
Abstract: A theory describing the acoustoionic interaction of shear horizontal (SH) surface waves with viscous conductive ionic liquid is presented. A Green's function formulation that accounts for the acoustoelectric interaction with ions and dipoles in the solution is obtained for the surface potential in terms of the liquid and piezoelectric crystal parameters. For dilute ionic solutions, simple closed-form expressions for the velocity change and attenuation are obtained in terms of liquid conductivity and dielectric constant and the piezoelectric coupling coefficient. It is shown that SH surface waves in particular and acoustic waves in general can be used to perform microanalysis of dilute ionic solutions, detecting conductivity, dielectric constant, and relaxation frequency. The analysis, which was done for a simple crystal class, the hexagonal (6 mm), shows results which compare very well with exact numerical computations. >
18 citations
TL;DR: In this paper, the structural properties of Na1/ammonia solution have been studied by means of a molecular dynamics simulation, the experimental density of pure liquid ammonia being used, and a free orientation of the ammonia molecules in the first solvation shell of the sodium ion has been found.
Abstract: The structural properties of Na1/ammonia solution have been studied by means of a molecular dynamics simulation, the experimental density of pure liquid ammonia being used. In contrast to the previous study for the lithium ion in liquid ammonia, a free orientation of the ammonia molecules in the first solvation shell of the sodium ion has been found. The effects of elevated temperature on the structure function of the cationic solvation shell could be observed clearly i.e., an increase in temperature leads to significant changes in molecular orientation and an increase in the average dipole moment of solvated ammonia. The intramolecular geometry changes of an ammonia molecule relative to the pure liquid were similar to those reported for Li1/ammonia solution.
16 citations
TL;DR: Ion chromatography was used to separate sodium and 1-methyl-3-ethylimidazolium cations in the buffered 1 methyl-3 -ethylimide-chloride (M3E)-aluminum chloride room-temperature molten salt system.
14 citations
TL;DR: In this article, a mixed Lewis-Bronsted acid ambient temperature chloroaluminate molten salt, in which both the Lewis and Bronsted acidity may be varied, has been investigated making use of a probe solute molecule.
Abstract: A mixed Lewis-Bronsted acid ambient temperature chloroaluminate molten salt, in which both the Lewis and Bronsted acidity may be varied, has been investigated making use of a probe solute molecule. The interaction of the proton and molten salt solvent with N,N-dimethylaniline has been investigated making use of electrochemistry and NMR spectroscopy. The ambient temperature chloroaluminate molten salt, composed of 1-ethyl-3-methylimidazolium chloride, ImCl, and aluminum chloride, is the underlying Lewis acid substrate, to which a proton source, ImHCl 2 , is added
9 citations
TL;DR: In this article, the reaction of some podocarpa-6,8,11,13-tetraenes with m-chloroperbenzoic acid in either a one-phase or a two-phase system with an aqueous buffer leads to epoxide opened products.
Abstract: The reaction of some podocarpa-6,8,11,13-tetraenes with m-chloroperbenzoic acid in either a one-phase system or a two-phase system with an aqueous buffer leads to epoxide-opened products. Successful epoxidations have been achieved in high yield by using the neutral oxidant dimethyldioxiran. The hydroboration -oxidation of methyl 12-benzyloxypodocarpa-6,8,11,13-tetraen-19-oate has been examined.
8 citations
TL;DR: In this paper, a microscopic model for the non-metal-metal transition on dissolving metals in molten salts is presented. But the model is restricted to a specific case of solutions of sodium metal in molten cryolite (AlF3 3NaF).
Abstract: The continuous nonmetal-metal transition, which occurs on dissolving metals in molten salts, may be shifted to higher metal concentration in solutions involving polyvalent metal ions by the possibility that these metals go into lower oxidation states. We evaluate a microscopic model for these processes in the specific case of solutions of sodium metal in molten cryolite (AlF3 3NaF). The structure of the ionic melt is understood and calculable at the microscopic level in terms of a dominant six-fold coordinated trivalent state of the A1 ion (the (AlF6)3- complex) with some admixture of a four-fold coordinated trivalent state (the (AlF4)− complex). The sodium metal is assumed to enter the ionic liquid in the form of monovalent ions and electrons. Our calculations demonstrate how these added components break up the structure of the ionic melt to yield localization by the formation of Al ions in reduced valence states, and provide order-of-magnitude estimates for the free-energy changes involved in t...
5 citations
TL;DR: In this article, the liquid phase thermal degradation of a number of compounds which model the common defect groups found in pvc has been investigated, including 2-chloroalk-3-enes and 4-chlorosalk-2-enes, and the degradations were confirmed to be accelerated by glass surfaces, hydrogen chloride and polar solvents.
Abstract: The liquid phase (neat and solution) thermal degradation of a number of compounds which model the common defect groups found in pvc has been investigated. Compounds with halogen atoms at tertiary positions have stabilities similar to allylic halides. However, there was nearly a tenfold difference in the rate of reaction between the positionally isomeric 2-chloroalk-3-enes and 4-chloroalk-2-enes. Compounds with unsaturation within a longer chain or compounds lacking a terminal methyl group are somewhat less reactive. The dehydrochlorination reaction was confirmed to be accelerated by glass surfaces, hydrogen chloride and polar solvents.
3 citations
TL;DR: In this article, the authors describe a scenario in which a group of individuals are separated into two groups: the first group is composed of individuals, and the second group is comprised of entities.
Abstract: アンモニウムイオン基を構成基とするポリエチレンイミン系及びイオンコンプレックス系のイオン性高分子液晶を合成し, それらの熱的性質及び配向特性について調べた. またアンモニウムイオン基をもつモデル低分子液晶も合成して比較検討した. 合成したイオン性高分子液晶及びモデル低分子液晶はすべてエナンシオトロピックなスメクティック相を示した. アンモニウムイオン基の導入はスメクティック相の熱安定性を向上させ, 垂直配向構造の自発的形成を促進させることが明らかとなった. 液晶相において自発的に形成された垂直配向構造は固体状態で保持された. 垂直配向試料のX線回折測定から, スメクティック層内ではイオン性基部分及びメソゲン基部分はそれぞれ分離して凝集状態を形成することが見いだされた. イオンコンプレックス系においても安定なスメクティック相が形成されることから, イオン結合を用いた機能複合系液晶の構築が可能であることがわかった.
2 citations
TL;DR: In this paper, the annelation of bis (quinone monoacetals) with the anions of substituted 3-cyanophthalides has been studied, and derived derivatives of quinizarin linked by polyether chains.
Abstract: Derivatives of quinizarin linked by polyether chains have been prepared by the annelation of bis (quinone monoacetals) with the anions of substituted 3-cyanophthalides.
2 citations
TL;DR: In this article, a mixed Lewis-Bronsted acid ambient temperature chloroaluminate molten salt, in which both the Lewis and Bronsted acidity may be varied, has been investigated making use of a probe solute molecule.
Abstract: A mixed Lewis-Bronsted acid ambient temperature chloroaluminate molten salt, in which both the Lewis and Bronsted acidity may be varied, has been investigated making use of a probe solute molecule. The interaction of the proton and molten salt solvent with N,N-dimethylaniline has been investigated making use of electrochemistry and NMR spectroscopy. The ambient temperature chloroaluminate molten salt, composed of 1-ethyl-3-methylimidazolium chloride, ImCl, and aluminum chloride, is the underlying Lewis acid substrate, to which a proton source, ImHCl 2 , is added
1 citations