Physicochemical Properties of Ionic Liquids

Jennifer L. Anthony, Joan F. Brennecke, John D. Holbrey, Edward J. Maginn, 

Robin D. Rogers, Paul C. Trulove, Ann E. Visser, and Tom Welton 

It should also be noted that terms such as high temperature and low temperature are also subjective, and depend to a great extent on experimental context. If we exclusively consider ionic liquids to incorporate an organic cation, and further limit the selection of salts to those that are Hquid below 100 °C, a large range of materials are still available for consideration. 

The utility of ionic liquids can primarily be traced to the pioneering work by Osteryoung et al. [3] on N-butylpyridinium-containing, and by Wilkes and Hussey [4—6] on l-ethyl-3-methylimidazoHum-containing ionic Hquids for electrochemical studies. These studies have strongly influenced the choice of ionic Hquids for subsequent research [7]. The vast majority of work pubHshed to date on room-temperature ionic Hquids relates to N-butylpyridinium and l-ethyl-3-methyHmidazoHum [EMIM] tetrachloroaluminate(III) systems. The large variety of available ion combi- 

It should be emphasized that ionic Hquids are simply organic salts that happen to have the characteristic of a low melting point Many ionic Hquids have been widely investigated with regard to applications other than as liquid materials as electrolytes, phase-transfer reagents [12], surfactants [13], and fungicides and biocides [14, 15], for example. 

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Song Y, Liu L, Zhu X F, et al. Physicochemical properties of ionic liquids based on imidazolium/pyrrolidinium cations and maleate/ phthalate anions. Solid State Ionics. 2008. 179, 516-521. 

Physicochemical Properties of Ionic Liquids Melting Points and Phase Diagrams... 

How does one identify a promising non-synthetic applicationfor ionic liquid technoU Our answer to this question four years ago was also very vague. We made some general comments that researchers on synthetic and non-synthetic applications should collaborate to broaden the range of general physicochemical properties of ionic liquids and speculated that such better data ranges would lead to the identification of new non-synthetic applications. 

Liang C, Yuan CY, Warmack RJ, Barnes CE, Dai S (2002) Ionic Uquids a new class of sensing materials for detection of oiganic vapors based on the use of a quartz crysteil microbalance. Anal Chem 74 2172-2176 MankM, Stahl B, Boehm G (2004) 2,5-Dihydroxybenzoic acid butylamine and other ionic liquid matrixes for enhanced MALDI-MS analysis of biomolecules. Anal Chem 76 2938-2950 Mantz AR, Trulove PC (2003) Physicochemical properties of ionic liquids. In Wasserscheid P, Welton T (eds) Ionic liquids in synthesis. Wiley, Berlin, pp 75-143... 

Zhou, Q., Lu, X., Zhang, S. and Guo, L., Physicochemical properties of ionic liquids, in Ionic Liquids Further UnCOILed Critical Expert Overviews, eds. N.V Plechkova and K.R. Seddon, John Vtiley Sons, Inc., Hoboken, NJ (2013). 

In summary, suppressed diffusion of nanoparticles in highly viscous media, such as ionic liquids, leads to an increase in the lifetime by a factor of 10-1000 comp>ared to classic low viscous solvents, contributing significantly to the stabilization of colloidal nano-sized particles. As mentioned above, ionic liquids can also serve as electrostatic and steric stabilizers. The physicochemical properties of ionic liquids and, thus, the properties of ionic liquid stabilized nanoparticles can be readily adjusted by changing cations and anions. Compared to polymers, ionic liquids as stabilizers for nanoparticles provide some particular advantages. Non-ionic polymers (in contrast to polyelectrolytes) have no ionic nature (only steric stabilization applies) and their ability to dissolve various compounds, for instance, metal precursors or substrates is limited vide infra). Thus, often an orj nic solvent is required, where both polymer, metal precursor and the substrate are soluble e.g., in case of applications in catalysis). The use of organic solvents can be avoided, when catalytic reactions are performed in neat ionic liquids (with dispersed nanoparticles). Reactions can also be conducted in neat substrate, where small amount of ionic liquid stabilized nanoparticles are added. 

Physicochemical properties of ionic liquid and refrigerant s binary solution 2.1 Vapor liquid equilibrium (VLE)... 

Tong J, Liu Q-S, Xu W-G, Fang F-W, Yang J-Z (2008) Estimation of physicochemical properties of ionic liquids l-aUcyl-3-methylimidazolium chloroaluminate. J Phys Chem B... 

Deng Y, Husson P, Delort V, Bess-Hoggan P, Sancehne M, Costa Gomes MF (2011) Influence of an oxygen functionalization on the physicochemical properties of ionic liquids density, viscosity, and carhon dioxide solubihty as a function of temperature. J Chem Eng Data 56 4194-4202... 

The physicochemical properties of ionic liquids (ILs) at 298.15 K could be estimated and predicted in terms of empirical and semi-empirical equations, as well as the interstice model theory. In the present study, the properties of molecular volume, density, standard molar entropy, lattice energy, surface tension, parachor, molar enthalpy of vaporization, interstice volume, interstice fractions, thermal expansion coefficient were discussed. These properties first were estimated through the data of experimental density and surface tension for 1-ethyl-3-methyhmidazolium ethylsulfate ([C2mim][EtS04]), l-butyl-3-methylimidazolium octylsulfate ([C4tnim][0cS04]) and l-ethyl-3-methylimidazolium... 

Physicochemical Properties of Ionic Liquids Containing A -alkylamine-Silver(l) Complex Cations or Protic N-alkylaminium Cations... 

In the present review, we refer to the systems of metallo-ILs having alkylamine or alkylethylenediamine ligands which are the structurally most simple and neutral amphiphilic ligands. Furthermore, alkylamines or alkylethylenediamines can provide protic ionic liquids. We here focus on the physicochemical properties of ionic liquids of N-alkylethylenediamines containing silver(I) ion or proton and compare the effects of alkylchains on the physicochemical properties between the silver(I)-ILs and the PILs. We emphasize the difference in the physicochemical properties between the alkylamines and alkylethylenediamines the latter is more advantageous to incorporate metal ions to the polar domains in the ILs than the former. 

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