Task-specific ionic liquids TSIL

Supported analogs of ionic liquid catalysts Task specific ionic liquids (TSIL) Telomerization in ILs... 

Recently, reports have appeared on a class of ILs known as task specific ionic liquids (TSIL). The term was introduced by J. H. Davis, Jr s group to refer to those ILs which have functional groups attached to them so as to give specific properties and functionalities. Thus, they not only perform specific functions like metal ion extraction,catalysisand capture of but also maintain the desired physical characteristics such as physical state, non-volatility, viscosity, etc. The implementation of TSILs further enhances the versatility of classical ILs where both reagent and medium are coupled. The union of reagent with medium has been... 

A task specific ionic liquid (TSIL) is defined as an ionic liquid which incorporates a covalently linked reactive functionality. This function confers to the assembly additional properties (chemical, optical, magnetic, physical or biological) which can then be employed to perform a specific task. If the melting points of these salts are above 100 °C they are called task specific onium salts (TSOSs) [17]. The latter constitutes a much larger family of compounds that include TSILs and all associations of cations and anions, regardless of their melting points. 

Task-specific ionic liquids (TSILs) represent a more advanced approach to the design of ionic liquids to be exploited in catalytic applications. Indeed, the structure of one partner of the ion pair is tailored in such a way to incorporate a functional group able to stabilise the catalytically active metal. A range of different functional groups have been installed on the cation moiety of onium salts, for example nitrile, thiok alcohol, acid, amide,52 urea. etc. Thus, the ionic liquid plays a double role, acting both as the reaction medium and as a stabilising ligand for the catalytically active species. Such a stabilisation, hopefully, should improve the catalyst half-life and afford better results compared to unfunctionalised ionic liquids. 

Owing to their unique physico-chemical properties (solvation, polarity, structure), ILs have been proved to be more than physical solvents, providing an unusual coulombic environment where kinetic constants, activation energies and thermodynamic parameters may be strongly modified with respect to their values in traditional molecular solvents. Indeed, tailored ILs with supplementary functionalities, usually referred to as task-specific ionic liquids (TSILs), can chemically interact with the catalyst, for example acting as an activator, a ligand, etc. 

Task-specific Ionic Liquids (TSILs) in Batch Processing... 

Cf-Aminophosphonates can act as peptide mimetics, enzyme inhibitors, antibiotic and pharmacological agents, and as herbicides, fungicides, insecticides, and plant growth regulators. Akbari et al. have demonstrated that a readily available, highly efficient, task-specific ionic liquid (TSIL) can be used as a recyclable catalyst for the synthesis of a-aminophosphonates from aldehydes and ketones in water (Fig. 12.44) [30]. This is the first report of a functionalized ionic liquid-catalyzed synthesis of a-aminophosphonates. 

A new strategy for the synthesis of polyhydroquinolines from task-specific ionic liquids (TSIL) as a soluble support was developed. The preparation of the polyhydroquinolines by a three-component reaction was achieved by using ionic liquid... 

Another developing approach for using ILs in metal ions separation was first initiated by Davis, who introduced the term task-specific ionic liquid (TSIL) to describe I Ls prepared using the concept of increasing the IL aSinity of the extractants by incorporating the complexing functionality as an integral part of the IL [36]. 

Here we provide a comprehensive review of new task-specific ionic liquids (TSILs) and binary task-specific ionic liquids (BTSILs) as functional ionic liquids designed as alternate soluble supports for supported organic synthesis (SPOS) and combinatorial chemistry. The applications of these supports are based mainly on imida-zolium, ammonium and pyridinium salts. The versatility of the supports has been... 

The mechanism of extraction and the complexes that are formed depend on the ionic liquid concerned and are quite different than the mechanisms involved with conventional solvents. Knowledge of the mechanisms involved and the species formed would be necessary for comprehensive characterisation and modelling of two-phase extractors. Task specific ionic liquids (TSILs) could also play an important role in extractions, wherein the functional groups in both cations and anions would enhance the extraction efficiency and selectivity. Since most studies deal with single component extraction it would be extremely useful to investigate the performance of ionic liquids in the selective separation of a certain component from mixtures that simulate the actual nuclear waste. Finally, the possibility to recycle the actinides that are immobilized in the ionic hquids should be the next research area of the near future. 

During the last 10 years, various types of functionalized ionic liquids (Fig. 20.2) expressly categorized as being task-specific ionic liquids (TSILs) have been designed and synthesized for specific purposes such as catalysis, organic synthesis, separation of specific materials, and for the construction of nanostructured and ion conductive materials, amongst others. The salts are defined as functirmalized ionic liquids when they are ionic liquids in which a functional group (FG) is covalently tethered to (a) the cation (b) the anion, or (c) a zwiterionic form of the salt. It is typically the cation that bears the reactive moiety. 

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