In contrast to a recently expressed, and widely cited, view that “Ionic liquids are starting to leave academic labs and find their way into a wide variety of industrial applications”, we demonstrate in this critical review that there have been parallel and collaborative exchanges between academic research and industrial developments since the materials were first reported in 1914 (148 references)

Applications of ionic liquids in the chemical industry

Within the framework of green chemistry, solvents occupy a strategic place. To be qualified as a green medium, these solvents have to meet different criteria such as availability, non-toxicity, biodegradability, recyclability, flammability, and low price among others. Up to now, the number of available green solvents are rather limited. Here we wish to discuss a new family of ionic fluids, so-called Deep Eutectic Solvents (DES), that are now rapidly emerging in the current literature. A DES is a fluid generally composed of two or three cheap and safe components that are capable of self-association, often through hydrogen bond interactions, to form a eutectic mixture with a melting point lower than that of each individual component. DESs are generally liquid at temperatures lower than 100 °C. These DESs exhibit similar physico-chemical properties to the traditionally used ionic liquids, while being much cheaper and environmentally friendlier. Owing to these remarkable advantages, DESs are now of growing interest in many fields of research. In this review, we report the major contributions of DESs in catalysis, organic synthesis, dissolution and extraction processes, electrochemistry and material chemistry. All works discussed in this review aim at demonstrating that DESs not only allow the design of eco-efficient processes but also open a straightforward access to new chemicals and materials.

Deep eutectic solvents: syntheses, properties and applications

2.5. Stabilization of IL Emulsions by Nanoparticles 2623 3. Hydrogenations in ILs 2623 3.1. Hydrogenation on IL-Stabilized Nanoparticles 2623 3.1.1. Hydrogenation of 1,3-Butadiene 2623 3.1.2. Hydrogenation of Alkenes and Arenes 2624 3.1.3. Hydrogenation of Ketones 2624 3.2. Homogeneous Catalytic Hydrogenation in ILs 2624 3.3. Hydrogenation of Functionalized ILs 2625 3.3.1. Selective Hydrogenation of Polymers 2625 3.4. Asymmetric Hydrogenations 2626 3.4.1. Enantioselective Hydrogenation 2626 3.5. Role of the ILs Purity in Hydrogenation Reactions 2628

Catalysis in ionic liquids

Structure and nanostructure in ionic liquids.

Ionic liquids (ILs) are organic salts with melting points near room temperature (or by convention below 100 degrees C). Recently, their unique materials and solvent properties and the growing interest in a sustainable, "green" chemistry has led to an amazing increase in interest in such salts. A huge number of potential cation and anion families and their many substitution patterns allows the desired properties for specific applications to be selected. Because it is impossible to experimentally investigate even a small fraction of the potential cation-anion combinations, a molecular-based understanding of their properties is crucial. However, the unusual complexity of their intermolecular interactions renders molecular-based interpretations difficult, and gives rise to many controversies, speculations, and even myths about the properties that ILs allegedly possess. Herein the current knowledge about the molecular foundations of IL behavior is discussed.

Understanding Ionic Liquids at the Molecular Level: Facts, Problems, and Controversies

Paradigm confirmed: the first use of ionic liquids to dramatically influence the outcome of chemical reactions.

Mutually immiscible ionic liquids

The recently discovered class of ionic liquids—mutually immiscible ionic liquids—are explored in this work for their first practical application: the separation of aromatic and aliphatic hydrocarbons by solvent extraction. For this preliminary approach, benzene and hexane were chosen as representatives of each group of hydrocarbons; the ionic liquids 1-ethyl-3-methylimidazolium bis{(trifluoromethyl)sulfonyl}amide and trihexyl(tetradecyl)phosphonium bis{(trifluoromethyl)sulfonyl}amide, which are both liquid at room temperature and hydrophobic, were selected as potential solvents. Liquid–liquid equilibrium experiments were carried out at 25 °C for the quaternary system formed by the two hydrocarbons and the two ionic liquids. Typical extraction parameters were calculated and analysed in order to evaluate the possibilities of the mutual immiscible ionic liquids in accomplishing the separation target. A comparison with the case of using just one of the ionic liquids was made.

Suhas Prabhakar Katdare

Papers

Paradigm confirmed: the first use of ionic liquids to dramatically influence the outcome of chemical reactions.

Mutually immiscible ionic liquids

Application of mutually immiscible ionic liquids to the separation of aromatic and aliphatic hydrocarbons by liquid extraction: a preliminary approach

Alternating copolymerisation of styrene and carbon monoxide in ionic liquids

Phase equilibria of mixtures of mutually immiscible ionic liquids