Search

Solvate ionic liquids (SILs) composed of glymes and Li salts are potential electrolyte materials for Li ion batteries. Safety and durability of SIL‐based batteries can be realized by competing characters of solvate cations. Solvate structure of Li+ should be stable in the bulk to be nonvolatile, and its desolvation should occur rapidly on electrode surfaces which is considered as a rate‐limiting step in charging or discharging. To investigate such characters, potential‐dependent interfacial structure of [Li(G4)][TFSA], equimolar mixture of tetraglyme and lithium bis(trifluoromethanesulfonyl)amide, on an Au electrode has been investigated at the molecular scale by using surface‐enhanced infrared absorption spectroscopy. Despite discrete solvate ion [Li(G4)]+ is stable in the bulk, partial desolvation of Li+ on the electrode was observed at around the potential of zero charge, much more positive than Li+ reduction reactions. The driving force of the partial desolvation can be ascribed to the breaking of isotropic dielectric environment in the vicinity of the electrode, where image charge induced on the electrode surface stabilizes the partially desolvated structure enabling shorter Li+‐electrode distance. [ABSTRACT FROM AUTHOR]

Equimolar mixtures of glymes and organic lithium salts are known to produce solvate ionic liquids, in which the stability of the [Li(glyme)]+ complex plays an important role in determining the ionic dynamics. Since these mixtures have attractive physicochemical properties for application as electrolytes, it is important to understand the dependence of the stability of the [Li(glyme)]+ complex on the ion dynamics. A series of microsecond molecular dynamics simulations has been conducted to investigate the dynamic properties of these solvate ionic liquids. Successful solvate ionic liquids with high stability of the [Li(glyme)]+ complex have been shown to have enhanced ion dynamics. Li-glyme pair exchange rarely occurs: its characteristic time is longer than that of ion diffusion by one or two orders of magnitude. Li-glyme pair exchange most likely occurs through cluster formation involving multiple [Li(glyme)]+ pairs. In this process, multiple exchanges likely take place in a concerted manner without the production of energetically unfavorable free glyme or free Li+ ions. [ABSTRACT FROM AUTHOR]

A series of donor-acceptor p-nitro-p'-alkoxy (OR) substituted (E,E,E)-1,6-diphenyl-1,3,5-hexatrienes were prepared and their properties and crystal structures investigated. The flouresence spectra of these crystals were red-shifted relative to those for the solutions in low polar solvents, which can be attributed to the planarization of molecules in the solid state and to the strong intermolecular interactions in crystals.

The quantitative information on the formation on ionic aggregates in room-temperature Ionic Liquids (RTILs) based on the ratios of molar conductivity values ([A.sub.imp]/[A.sub.NMR], where [A.sub.imp] is the molar conductivity obtained by electrochemical impedance measurements and [A.sub.NMR] is that calculated from the pulse-field-gradient spin-echo NMR (PGSE-NMR) ionic self-diffusion coefficients and the Nernst-Einstein equation is reported. A decrease in ([C.sub.eff]) effective ionic concentration of the RTILs is well correlated with the normal boiling point and distillation rate, whereas the liquid-state dynamics is controlled by a subtle balance between the electrostatic and other intermolecular forces.

The CCSD(T) level interaction energies of CH/pi complexes at the basis set limit are estimated. The weak directionality has indicated that the hydrogen atom of the interacting C-H bond is not essential for the attraction and that the typical CH/pi interaction does not play a key role in determining the molecular orientation in molecular assemblies.

A series of room-temperature ionic liquids (RTILs) were prepared with different cationic structures, combined with an anion and the thermal property, density, self-diffusion coefficients of the cation and anion, viscosity, ionic conductivity were measured over a wide temperature range. It was found that the relative cationic and anionic self-diffusion coefficients for the RTILs appear to be influenced by the shape of cationic structure and that the microscopic ion dynamics and ionic state significantly contributes to the macroscopic physicochemical properties of the ionic liquids.

The ARS-E model was used for calculating the intermolecular interaction energy of hexafluorobenzene-benzene. The largest and most negative energy of -5.38 kcal/mol was observed in the slipped-parallel complex.

Single crystal of a series of (Z,E,Z)-1,6-diphenylhexa-1,3,5-triene 4,4'-dicarboxylic acid dialkyl esters that were prepared and their crystal structures and photoisomerization behaviors that were systematically investigated is described. The conformational flexibility of the alkyl chains made the large change in the trienegeometry in the lattice possible, leading to the enhancement of the photoreactivity in the crystalline state.

(Super 1)H and (super 13)C NMR studies have proved interactions between a thicarbonyl group and a pyridinium nucleus, and between a carbonyl group and a pyridinium nucleus. The experimental results suggested the existence of attractive (C=S)...Py(super +) and (C=O)...(Py(super +) interactions in solution and in crystal.

The interaction energies of the alkaline-earth-metal dication/benzene complexes were calculated at the MP2 level using the 6-311G-basis set. The calculations of benzene under an electric field show that the electric field produced by the diction is a cause of the C-C bond elongation in the alkaline-earth-metal dication/benzene complexes.

Calculation of intermolecular interaction energies of 14 orientation CHF3 dimers is done with electron correlation correction by the MP2 method. Electron correlation correction increases the attraction considerably, which indicates that the dispersion interaction is important for the attraction.

The interaction energy calculation of the thiophene dimmer is presented by using very large basis sets near saturation. The estimation of MP2 and CCSD(T) level interaction energies at the basis set limit are described by using model chemistry.

Research is presented concerning the use of density functional theory calculations to investigate the intermolecular interaction energy of the water-crownophane complex. The binding energy of the water is discussed.

Interactions between the pi face of benzene and ammonia are reported as a model of NH/pi interaction.

High-level ab initio calculations were used to evaluate the CH/varPi interaction of model systems and benzene.

High-level ab initio calculations have been used to investigate the torsional potentials of methoxy and hydroxyl groups of omichron-hydroxyanisole. It was established that the intramolecular bond significantly stabilizes the energy minimum structure.

Estimation of the intermolecular interaction energies has been carried out by means of ab initio calculations of C (sub)2 H (sub)4 - CH (sub)4 and C (sub)2 H (sub)6 - CH (sub)4 dimer orientations. The role of the electrostatic, dispersion and charge transfer interactions between aliphatic C-H bond and pi-system has been discussed.