Ionic liquids properties

ILs are fluids composed solely of ions and, and by consensus, have a melting point below 100 ILs are the focus of interest of a growing community for their unique properties such 

One of the largest family of ILs, now with innumerable representatives, stems from the early study of acidic chloroaluminates ([AICI4] , [ALCly] ) of the delocalised cations based on imidazolium derivatives  

Numerous ILs based on substituted imidazolium cations and classic anions such as [BFJ , [CFsSOs], [PFg] have been developed since the early 

The reduction potential of the imidazolium cation, however, limits the use this family of ILs in some electrochemical applications such as lithium batteries. 

The acidity of the C2 proton (indicated in the scheme above) is estimated as pKa = 24, and this corresponds to a reduction potential of 1.5 V vs Li Li°. The methylation of the C2 proton increases the reduction potential by 300 mV however, this is still not sufficiently negative for lithium battery applications and thus such ILs require the use of additives such as vinylene carbonate (VC), which form a stable solid-electrolyte interphase (SEI) layer, in order to be viable.f  

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At this stage of development, loiowledge of ionic liquid properties is patchy, to say the least. For some applications only limited, very specific information is needed to allow the translation of a research project into technical reality (mostly non-synthetic applications). For others (mostly synthetic applications), a lot more detailed information, sldlls, and data are required to make the technology feasible. This process takes time, even though the ever growing ionic liquid community has already added a lot of information to the ionic liquid toolbox . 

IONIC LIQUID PROPERTIES ARE IONIC LIQUIDS GREEN ... 

These relations are summed up in some of the classical equations of electrochemistry, which were derived by consideration of dilute aqueous solutions in which complete dissociation into independently moving ions could be assumed. Although these solutions present a rather different physical situation from that of solvent-free ionic liquids, the laws developed for their description remain very relevant to the description of the ionic liquid properties. The main difference is that the notion of dissociation is more obscure. In ionic liquids the state of dissociation must be decided by operational criteria, as we outline below. 

Jacquemin J, Nancarrow P, Rooney DW et al. (2008) Prediction of ionic liquid properties. II. Volumetric properties as a function of temperature and pressure. J Chem Eng Data 53 2133-2143... 

Supported ionic liquid catalysis is one of the main examples of SLPC adopted [120] to take advantage of ionic liquid properties without the drawbacks evidenced in Section 2.3.6. The viability of this concept has been confirmed by several studies that have successfully confined various ionic phases to the surface of support materials and explored their potential catalytic applications. Although most of the evaluated supports were silica based, several studies have focused on polymeric materials, including membranes. These materials were prepared by using two different immobilization approaches. The first involves the covalent attachment of ionic liquids to the support surface whereas the second simply deposits the ionic liquid phases containing catalytically active species on the surface of the support. 

Greaves TL, Drummond CJ (2008) Protic ionic liquids properties and applications. Chem Rev 108 206-237... 

Deng YQ (2006) Ionic liquids-properties, preparation and application. China SINO-PEC Press, Beijing (in Chinese)... 

Ionic liquids introduce a new possibility in this regard, as their ability to provide dissolution is often unpredictable and sometimes useful. These ionic liquid properties have been used recently to achieve incorporation of dye molecules into polyterthiophene.17... 

Nucleophilic substitution reactions in ionic liquids have recently been the subject of both synthetic [33] and kinetics and mechanistic studies [34]. Ionic liquids may be efficient promoting media for nucleophilic displacement reactions and important information about the ionic liquid properties has been obtained from the study of these reactions. The kinetic investigation of bimolecular substitution reactions of the halides on methyl p-nitrobenzenesulfonate, recently carried out by Wdton et al. [34] in several ionic media characterized by the same anion, [Tf2N] , and different cations ([BMIM]+, [BMMIMJ+ and [BMPY]+) or by the same cation, [BMIM] and different anions ([BF4] , [PFs] , [SbF ] and [Tf2N] ), has shovrathat the halides nucleophilicities depend on the ionic liquid structure (Scheme 5.1-7). 

Today, much more data on the physicochemical properties of pure ionic liquids are available. We have learned which ionic liquid properties are well tuneable and which properties are more or less intrinsic to the group. Even a prediction of the properties of mixtures of organic substances and ionic liquids with respect to solubility, miscibility and evaporation properties has become possible to some extent. The Cosmotherm methodology - a molecular modelling-based approach [20] - has, for example, already shown some promise in this respect. Today this method is used by a number of groups for the prediction of trends in the structural optimization of ionic liquids, in particular for extraction [21] and extractive distillation [22], with some success. However, more work is necessary to further develop and refine such methods for them to become fully reliable, quantitative tools for all types of ionic... 

Very low vapor pressure Purification may be a challenge purification methods must be optimized Ionic Uquid impurities must be controlled, determined and quantified these impurities may significantly affect ionic liquid properties The removal of ionic liquids from reaction products may be difficult... 

Kadokawa, J. Preparation of functional ion gels of polysaccharides with ionic hquids. In Handbook of ionic liquids properties, applications and hazards Mun, J. Sim, H., Eds. Nova Science Publishers Hauppauge, 2012, pp 455-466. 

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