L-ethyl-3-methylimidazolium hexafluorophosphate

The microwave-assisted thionation of amides has been studied by Ley and coworkers using a polymer-supported thionating reagent [115]. This polymer-supported amino thiophosphate serves as a convenient substitute for its homogeneous analogue in the microwave-induced rapid conversion of amides to thioamides. Under microwave conditions, the reaction is complete within 15 min, as opposed to 30 h by conventional reflux in toluene (Scheme 7.95). The reaction has been studied for a range of secondary and tertiary amides and GC-MS monitoring showed that it proceeded almost quantitatively. More importantly, this work was the first incidence of the use of the ionic liquid l-ethyl-3-methylimidazolium hexafluorophosphate... 

Shariati, A. and Peters, C. J., High-pressure phase behavior of systems with ionic liquids Measurements and modeling of the binary system fluoroform + l-ethyl-3-methylimidazolium hexafluorophosphate, /. Supercrit. Fluids, 25, 109, 2003. 

Alavi S, Thompson DL (2005) Molecular dynamics studies of melting and some liquid-state properties of l-ethyl-3-methylimidazolium hexafluorophosphate [emim][PF6]. J Chem Phys 122 154704-154712... 

Fuller, J., Carlin, R.T., De Long, H.C. and Haworth, D., Structure of l-ethyl-3-methylimidazolium hexafluorophosphate - model for room-temperature molten salts, Chem. Commun. (3), 299-300 (1994). 

In 2001, Hanke, Price and Lynden-BelP were the first to conduct an atomistic simulation of compovmds that can be called ionic liquids under our definition. They used molecular dynamics to model the crystalline state of 1,3-dimethylimidazolium chloride ([Cimim][Cl]), 1,3-dimethylimidazolium hexafluorophosphate ([CimimllPFg]), l-ethyl-3-methylimidazolium chloride ([C2mim][Cl]), and l-ethyl-3-methylimidazolium hexafluorophosphate ([C2 mimJlPFg]). They also modeled the liquid state of [Cimim][Cl] and [Cimim] [PFg], both of which are relatively high melting substances. Because of this (and the need to speed dynamics and thus limit computation times), the liquid simulations were carried out at temperatures between 400 and 500 K. The form of the potential function they used was... 

Abbott, A.P. (2005) Model for the conductivity of ionic liquids based on an infinite dilution of holes. ChemPhysChem, 6, 2502-2505. McCrary, P.D. and Rogers, R.D. (2013) l-Ethyl-3-methylimidazolium hexafluorophosphate from ionic liquid... 

Shim, Y, Jeong, D., Choi, M. Kim, H. (2006). Rotational dynamics of a diatomic solute in the room-temp)erature ionic liquid l-ethyl-3-methylimidazolium hexafluorophosphate, /. Chem. Phys. 125(6) 061102. 

Lipases from C. antarctica and P. cepacia showed higher enantioselectivity in the two ionic liquids l-ethyl-3-methylimidazolium tetrafluoroborate and l-butyl-3-methylimidazolium hexafluoroborate than in THE and toluene, in the kinetic resolution of several secondary alcohols [49]. Similarly, with lipases from Pseudomonas species and Alcaligenes species, increased enantioselectivity was observed in the resolution of 1 -phenylethanol in several ionic liquids as compared to methyl tert-butyl ether [50]. Another study has demonstrated that lipase from Candida rugosa is at least 100% more selective in l-butyl-3-methylimidazolium hexafluoroborate and l-octyl-3-nonylimidazolium hexafluorophosphate than in n-hexane, in the resolution of racemic 2-chloro-propanoic acid [51]. 

Ethyl diazoacetate is a frequently encountered carbene donor for the methylenation of imines. For example, the imine derived from -chlorobenzaldehyde 589 is converted to the tfr-aziridinyl ester 590 upon treatment with ethyl diazoacetate in the presence of lithium perchlorate <2003TL5275>. These conditions have also been applied to a reaction medium of the ionic liquid l- -butyl-3-methylimidazolium hexafluorophosphate (bmimPF6) with excellent results <2003TL2409>. An interesting enantioselective twist to this protocol has been reported, in which a diazoacetate derived from (iJ)-pantolactone 591 is used. This system was applied to the aziridination of trifluoro-methyl-substituted aldimines 593, which were prepared in situ from the corresponding aminals 592 under the catalysis of boron trifluoride etherate to give aziridines 594 (Scheme 143) <2003TL4011>. 

The fluorescent probe 4-aminophthalimide (63) as well as its /V,/V-diethyl homomorph (89) were used by Samanta and coworkers148 149 to study the polarity and fluorescence dynamics in l-alkyl-3-methylimidazolium salts. The alkyl groups were variously ethyl, butyl and octyl and the anions were nitrate, tetrafluoroborate, hexafluorophosphate and bis(triflyl)imide. Similar conclusions were reached concerning the effects of alkyl chain length and anion as those obtained by Carmichael and Seddon142 using Nile Red. The solvation dynamics were found to depend on the viscosity of the media. Further use of 63 in l-butyl-3-methylimidazolium hexafluorophosphate was reported by Ingram and... 

Salts like [emim]BF can be prepared by metathesis of l-ethyl-3-methylimidazolium iodide [anim]l with silver tetrafluoroborate Ag[BFJ that offers greater moisture stability and immiscibility with a number of organic solvents. Similarly, l-ethyl-3-methyUmidazohum hexafluorophosphate [anim]PFg can be prepared by reaction of... 

The moisture- and air-stable ionic liquids, l-butyl-3-methylimidazolium tetra-lluoroborate [bmim]BF and l-butyl-3-methylimidazolium hexafluorophosphate [bmim]PFg, were used as green recyclable alternatives to volatile organic solvents for the ethylenediaimnonium diacetate-catalyzed Knoevenagel condensation between aldehydes or ketones with active methylene compounds. As described by Su et al. [57], the ionic hquids containing a catalyst were recycled several times without decrease in yields and reaction rates. In the case of 2-hydroxybenzaldehyde, the reactions led to the formation of 3-substituted coumarin derivatives in high yields of up to 95% (Scheme 17.11). When ethyl cyanoacetate was used, 2-imino-27f-l-benzopyran-3-carboxyhc acid ethyl ester was formed. 

BmimHFP and BmimPF l- -butyl-3-methylimidazolium hexafluorophosphate BmiBF l-butyl-3-methyliniidazo-Uum tetrafluoroborate BmimPF l-n-butyl-3-methylimidazolium hexafluorophosphate CjmimNTFj and EmiraNTF l-ethyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide EmimBF polyethylene-supported l-ethyl-3-methylimidazolium tetrafluoroborate EmiraNTF l-ethyl-3-methyUmidazolium bis(trifluoromethylsulfonyl)imide Source Data from Stetter et al. (2011)... 

Non-aqueous electrolytes containing salts of alkyl substituted cyclic delocalized aromatic cations. Certain polyatomic anions, preferably PF " are dissolved in high conducting organic liquids such as alkyl carbonate solvents or liquid SC at concentrations >1M. Salt of l-ethyl-3-methylimidazolium and hexafluorophosphate (PF -) is reported to have high conductivity of less than 13 mS/cm, electrochemical stability >2.5 V, and high thermal stability >100°C. High capacitance of >100 F/g is obtained when used with activated carbon electrodes. 

In this chapter, we give an account of our recent MD and theoretical analysis of electron transfer" (ET) and SnI ionization" reactions in RTILs. Specifically, we consider the unimolecular ET of a model diatomic reaction complex in l-butyl-3-methyldicyanamide (BMI" DCA ) and ionization of 2-chloro-2-methylpropane in 1-ethyl-3-methylimidazolium hexafluorophosphate (EMI+PEg ). The influence of the RTIL environment on free energetics and dynamics of these reactions is described with attention paid to its similarities to and differences from the conventional polar solvents. The MD results for barrier crossing dynamics on reaction kinetics are analyzed via the Grote-Hynes (GH) theory and compared with the transition state theory (TST) and Kramers theory predictions. 

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