A short history of ionic liquids—from molten salts to neoteric solvents

Abstract

Ionic liquids, defined here as salts with melting temperatures below 100 °C, evolved from traditional high temperature molten salts. Some materials we would now recognize as ionic liquids were observed as far back as the mid 19th century. The quest for useful molten salts with lower melting temperatures led to inorganic chloroaluminates, to organic chloroaluminates, then to the water and air stable salts now being developed for green chemistry applications.

Triazolium-Based Energetic Ionic Liquids

“…Despite this easily understandable focus on the novel solvent properties of stable ILs, it is good to remember 11,12 that ILs are neither new materials nor are they required to be stable or are limited to use as solvents. Indeed, the well-known and undesired "red oil" appearing during Friedel-Crafts reactions is an ionic liquid containing an Al 2 Cl 7 -anion.…”

The simulation of imidazolium-based ionic liquids†

“…The dipole moment of the cations using the derived point charges reproduced the ab-initio dipole 6 ]. The geometry of the cation and PF 6 -anion were determined from B3LYP/6-311+G(d) level calculations.…”

“…[9] These parameters have also been used as the basis for calculations on the melting point of 6 ], bond lengths and angles were frozen or adjusted respectively to those of the X-ray structure. [23] The simulated unit cell parameters and solid state density were found to be within 1% of the experimental values.…”

“…[1] Thus ionic liquids are potentially useful in a large range of processes and are good candidates for use in synthetic, catalytic, separation and electrochemical processes, possibly at an industrial scale. A selection of reviews on the synthesis and properties of ionic liquids include, [1][2][3][4][5][6][7][8] this list is by no means exhaustive.…”

Ionic liquids as green reaction media for synthesis of poly(aryl ether ketone)s

“…All of the imidazolium based-ionic liquids used in this work were synthesized according to known procedures [14,15]. The structures of the ionic liquids were confirmed by 1 H NMR, FTIR and Elemental Analysis.…”