Structure neat ionic liquids

The highly detailed results obtained for the neat ionic liquid [BMIM][PFg] clearly demonstrate the potential of this method for determination of molecular reorienta-tional dynamics in ionic liquids. Further studies should combine the results for the reorientational dynamics with viscosity data in order to compare experimental correlation times with correlation times calculated from hydrodynamic models (cf [14]). It should thus be possible to draw conclusions about the intermolecular structure and interactions in ionic liquids and about the molecular basis of specific properties of ionic liquids. 

Mele, A., Romano, G., Giannone, M. et al.. The local structure of ionic liquids Cation-cation NOE interactions and internuclear distances in neat [bmim][BF4] and [bdmim][ BFJ, Angew. Chem. Int. Ed., 45,1123, 2006. 

Addition of thiophenols to chalcones in [bmim]PF6, catalysed by L-proline and cinchonine in CH2CI2, afforded products with <16% and 26% ee, respectively. The latter addition also occurred in neat ionic liquids in the absence of the latter catalysts but the rate of the reaction depended considerably on the structure of the ionic liquid.129... 

Atomistic Simulations of Neat Ionic Liquids - Structure and Dynamics... 

J. Antony, D. Mertens, T. Breitenstein, A. Doelle, P. Wasserscheid, W.R. Carper, Molecular structure, reorientational dynamics, and intermolecular interactions in the neat ionic liquid l-butyl-3-methylimidazolium hexafluorophosphate. Pure Appl. Chem. 76 (1) (2004) 255-261. 

Zhou, W., Inoue, S., Iwahashi, T., Kanai, K., Seki, K., Miyamae, T., Kim, D., Katayama, Y. and Ouchi, Y., Double layer structure and adsorption/desorption hysteresis of neat ionic liquid on Pt electrode surface - An in-situ IR-visible sum-frequency generation spectroscopic study, Electwchem. Commun. 12, 672-675 (2010). 

The balance of this Introduction will be committed to an overview of the chemical structures and macroscopic properties of ionic liquid systems. Section II provides a brief overview of the properties of high temperature molten salts, to provide a reference against which room temperature species may be compared. Section III considers the liquid structure and dynamics of neat ILs, and Sections IV and V discuss their operation as solvents at the microscopic level. 

The theory is based on two observations. First, solute-solvent interactions are characterized by dipole-ion interactions, and so are much weaker than the ion-ion interactions between solvent species. Thus, the presence of the solute dipole should not greatly perturb the liquid from the electrostatic structure of the neat liquid. Second, because the ionic liquid is a conductor, the electric field of the solute must be screened by the solvent. This observation has been confirmed... 

So far, there have been few published simulation studies of room-temperature ionic liquids, although a number of groups have started programs in this area. Simulations of molecular liquids have been common for thirty years and have proven important in clarifying our understanding of molecular motion, local structure and thermodynamics of neat liquids, solutions and more complex systems at the molecular level [1-4]. There have also been many simulations of molten salts with atomic ions [5]. Room-temperature ionic liquids have polyatomic ions and so combine properties of both molecular liquids and simple molten salts. 

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