Patent Publication Number: US-2011070486-A1

Title: Ionic liquid

Description:
TECHNICAL FIELD 
     The present invention relates to ionic liquids, and more particularly to ionic liquids having low viscosities and low melting points, and having high electrical conductivities. 
     BACKGROUND ART 
     Ionic liquids have attracted special attention for the past several years because of their potential uses as electrolytes for a variety of electrochemical devices, such as lithium secondary batteries, dye-sensitized solar cells, actuators, and electric double-layer capacitors; reaction media; and catalysts for organic syntheses. Compared with known organic liquid electrolytes, ionic liquids as electrolytes have the main advantages of non-flammability, non-volatility and high thermal stability. With regard to most of the ionic liquids so far reported, tetrafluoroborate (BF 4   − ) and bistrifluoromethylsulfonylamide([(CF 3 SO 2 ) 2 N] − , abbr. [TFSA] − , is the same as the ionic liquid previously named “bistrifluoromethylsulfonylimide”, abbr. TFSI; however, it is classified as an amide in this specification, as recently recommended by IUPAC.) have attracted attention as anions for ionic liquids because of their high electrochemical stabilities and thermal stabilities (Patent Literatures 1 and 2). [TFSA] −  salts, in particular, can easily form ionic liquids even with cations such as aliphatic quaternary ammonium that do not easily form ionic liquids because of their low charge dispersibility; and also have a high electrochemical stability compared with conventional imidazolium salts (Patent Literature 3). For these reasons, [TFSA] −  salts have enabled electrodeposition of lithium; however, they have not realized charging/discharging at a significantly increased charge/discharge current density when used in, for example, Li/LiCoO 2  cells. Bisfluoromethylsulfonylamide([(FSO 2 ) 2 N] − ; [FSA] − ), which is also an amide anion, has recently been reported to exhibit excellent basic physical properties and battery characteristics. However, because lithium salts (Non-Patent Literature 1) and ionic liquids (Non-Patent Literature 2) of Bisfluoromethylsulfonylamide have a low thermal stability, there is a need for ionic liquids that have higher thermal decomposition temperatures and provide improved battery characteristics. 
     Patent Literature 4 discloses salts containing fluorosulfonyl(trifluoromethylsulfonylamide) (FTA). However, Patent Literature 4 fails to disclose the melting points of the salts obtained in its Examples; therefore, the fact that these salts are ionic liquids is not established. 
     CITATION LIST 
     Patent Literature 
     
         
         PTL 1: Japanese Unexamined Patent Publication No. 2002-099001 
         PTL 2: Japanese Unexamined Patent Publication No. 2003-331918 
         PTL 3: Japanese Patent No. 2981545 PTL 4: Japanese Unexamined Patent Publication No. 2005-200359 
       
    
     Non-Patent Literature 
     
         
         NPL 1: K. Kubota, T. Nohira, T. Goto, R. Hagiwara,  Electrochem. Commun.,  10 (2008), pp. 1886-1888. 
         NPL 2: W. Yadong, K. Zaghib, A. Guerfi, F. F. C. Bazito, R. M. Torresi, J. R. Dahn,  Electrochim. Acta,  52 (2007), p. 6346. 
       
    
     SUMMARY OF INVENTION 
     Technical Problem 
     An object of the present invention is to provide ionic liquids having low viscosities and low melting points, and having high electrical conductivities and high thermal stabilities. 
     Solution to Problem 
     As a result of extensive research in view of the foregoing problems, the present inventors found that an ionic liquid comprising fluorosulfonyl(trifluoromethylsulfonylamide) (FTA) as an anion and a specific cation exhibits a low viscosity, a low melting point, a high electrical conductivity at low temperatures, and a relatively high thermal stability. 
     In summary, the present invention provides the following ionic liquids. 
     Item 1. An ionic liquid comprising fluorosulfonyl(trifluoromethylsulfonylamide) (FTA) as an anion and a cation selected from the following cations:
     tetramethylammonium (N1111);   ethyltrimethylammonium (N1112);   n-propyltrimethylammonium (N1113);   diethyldimethylammonium (N1122);   di-n-propyldimethylammonium (N1133);   triethylmethylammonium (N2221);   n-butyldiethylmethylammonium (N1224);   N,N-diethyl-N-methyl-N-(2-methoxyethyl)ammonium (DEME);   tetraethylammonium (N2222);   tetra-n-propylammonium (N3333);   tetra-n-butylammonium (N4444);   tetra-n-pentylammonium (N5555);   5-azoniaspiro[4.4]nonane (AS44);   dimethylimidazole (DMI);   propylmethylimidazole (PMI);   butylmethylimidazole (BMI);   N,N-dimethylpyrrolidinium (Py11);   N-methyl-N-ethylpyrrolidinium (Py12);   N-methyl-N-butylpyrrolidinium (Py14);   N,N-dimethyl-piperidinium (PP11);   N-methyl-N-ethyl-piperidinium (PP12);   N-methyl-N-propyl-piperidinium (PP13);   N-methyl-N-butyl-piperidinium (PP14);   tetraethylphosphonium (P2222); and   5-phosphoniaspiro[4,4]nonane (PS44).
 
Item 2. The ionic liquid according to Item 1, wherein the cation is tetraethylammonium (N2222) or triethylmethylammonium (N2221).
 
Item 3. The ionic liquid according to Item 1, wherein the cation is tetramethylammonium (N1111), ethyltrimethylammonium (N1112), or n-propyltrimethylammonium (N1113).
 
Item 4. The ionic liquid according to Item 1, wherein the cation is N,N-diethyl-N-methyl-N-(2-methoxyethyl)ammonium (DEME).
 
Item 5. The ionic liquid according to Item 1, wherein the cation is tetraethylphosphonium (P2222).
 
Item 6. The ionic liquid according to Item 1, wherein the cation is N-methyl-N-propyl-piperidinium (PP13).
 
Item 7. The ionic liquid according to Item 1, wherein the cation is 5-azoniaspiro[4.4]nonane (AS44).
   

     ADVANTAGEOUS EFFECTS OF INVENTION 
     The ionic liquids of the present invention are suitable for use in electrochemical devices, such as lithium secondary batteries, fuel cells, dye-sensitized solar cells, and electric double-layer capacitors; as solvents for chemical reactions; and as lubricants. 
    
    
     DESCRIPTION OF EMBODIMENTS 
     The structures of cations used in the invention are schematically shown below: 
     
       
         
         
             
             
         
       
     
     The structure of the anion used in the invention and the structures of anions for comparison are shown below: 
     
       
         
         
             
             
         
       
     
     The ionic liquids provided by the invention have melting points of 120° C. or less, preferably 80° C. or less, more preferably 50° C. or less, still more preferably 25° C. or less, even more preferably 0° C. or less, and most preferably −20° C. or less. For example, for use in fuel cells, a wide range of ionic liquids having melting points of 80° C. or less can be used. For use in energy device such as solar cells, lithium cells, and capacitors, and electrochemical devices such as electrochromic devices and electrochemical sensors, ionic liquids having melting points of preferably not more than room temperature (25° C.), and more preferably 0° C. or less, can be used. 
     Even if the melting points of ionic liquids used in the invention are not clearly observable, ionic liquids having glass transition temperatures of −70° C. or less, preferably −80° C. or less, more preferably −90° C. or less, and still more preferably −100° C. or less, can be considered equal to ionic liquids having melting points of the same temperatures. 
     In the invention, fluorosulfonyl(trifluoromethylsulfonylamide) (FTA; [(FSO 2 )(CF 3 SO 2 )N] − ) is used as an anion component of ionic liquids. This anion is a known compound, and can be produced according to, for example, Patent Literature 3. 
     An ionic liquid of the invention can be produced by mixing FTA ([(FSO 2 )(CF 3 SO 2 )N] − ) and a salt of a cation component such as an alkali metal ion (Na + , K + , Li + , Cs + , etc.), an alkaline earth metal ion (Ca 2+ , Mg 2+ , Ba 2+  etc.), or Bu 3 Sn +  with a salt containing a specific cation of the invention, followed by separation of the ionic liquid. For example, an ionic liquid containing FTA and a cation of the invention can be preferably obtained by mixing the salt of FTA([FSO 2 )(CF 3 SO 2 )N] − )H + , which is obtained by passage through an ion exchange resin, with a salt of (any of the cations of the invention) + (OH) − , followed by removal of the resulting water. When a desired molten salt is extractable, a salt-exchange reaction for obtaining the ionic liquid can be carried out by solvent extraction. 
     The cation component for an ionic liquid of the invention is selected from the following cations:
     tetramethylammonium (N1111);   ethyltrimethylammonium (N1112);   n-propyltrimethylammonium (N1113);   diethyldimethylammonium (N1122);   di-n-propyldimethylammonium (N1133);   triethylmethylammonium (N2221);   n-butyldiethylmethylammonium (N1224);   N,N-diethyl-N-methyl-N-(2-methoxyethyl)ammonium (DEME);   tetraethylammonium (N2222);   tetra-n-propylammonium (N3333);   tetra-n-butylammonium (N4444);   tetra-n-pentylammonium (N5555);   5-azoniaspiro[4.4]nonane (AS44);   dimethylimidazole (DMI);   propylmethylimidazole (PMI);   butylmethylimidazole (BMI);   N,N-dimethylpyrrolidinium (Py11);   N-methyl-N-ethylpyrrolidinium (Py12);   N-methyl-N-butylpyrrolidinium (Py14);   N,N-dimethyl-piperidinium (PP11);   N-methyl-N-ethyl-piperidinium (PP12);   N-methyl-N-propyl-piperidinium (PP13);   N-methyl-N-butyl-piperidinium (PP14);   tetraethylphosphonium (P2222); and   5-phosphoniaspiro[4,4]nonane (PS44).   

     All of these cations are known, and are available or can be produced according to known methods. 
     The molecular weight of FTA, which is the anion used in the invention, is between the molecular weights of TFSA ([(CF 3 SO 2 ) 2 N] − ) and FSA ([(FSO 2 ) 2 N] − ), which are anions having symmetric structures. Therefore, the physical properties of FTA, such as viscosity, electrical conductivity, and diffusion coefficient, are also expected to be intermediate between the physical properties of TFSA and FSA. However, because the FTA anion has an asymmetric structure, FTA is expected to have a dramatically lower melting point. The present inventors found that, particularly when FTA is combined with a specific cation of the invention, the resulting ionic liquid has a melting point that is lower than expected, and has an electrical conductivity closer to that of FSA salts than an intermediate between the conductivities of TFSA and FSA. Furthermore, with respect to thermal stability, which has been a drawback in FSA, the ionic liquid was found to exhibit a thermal stability generally higher than that of FSA. 
     The present inventors ascertained that the FTA anion used in the invention exhibits a high electrochemical stability comparable to that of known anions. The present inventors are the first to obtain ionic liquids containing N2222, AS44, and PS44, which have high symmetry, and whose salts generally have high melting points. The fact that a liquid was formed using the cation (N2222), from which ionic liquids could not heretofore be produced, indicates that the resulting ionic liquid is an amide salt that exhibits the highest oxidation stability of all the previously known amide salts. 
     The twenty-five cation components used in the invention (N1111, N1112, N1113, N1122, N1133, N2221, N1224, DEME, N2222, N3333, N4444, N5555, AS44, DMI, PMI, BMI, Py11, Py12, Py14, PP11, PP12, PP13, PP14, P2222, and PS44) may be used alone; however, a combination of two cations or more can further reduce the melting point and viscosity of the ionic liquid. 
     While FTA is used as an anion for ionic liquids, other anions may be additionally used as long as FTA is used as the main anion component. 
     EXAMPLES 
     The present invention will be described in more detail below with reference to Examples. 
     Example 1 
     Methods 
     For compound identification,  1 H NMR (500.2 MHz),  19 F NMR (470.6 MHz), and  11 B NMR (160.5 MHz) spectra were measured using a JEOL ECA-500 FT-NMR spectrometer. FAB-MS spectra were measured using a JEOL JMS-HX110/110A spectrometer. 
     Density: 
     The density of an ionic liquid was determined by measuring the weight of 1.0 mL of the ionic liquid at 25° C. three times. 
     Specific Conductivity: 
     The ionic conductivity (K) of a neat (solvent-free) ionic liquid was determined in a sealed conductivity cell by using a conductivity meter (Radiometer Analytical, model CDM230). 
     Viscosity: 
     The viscosity of a 0.6 mL sample at 25° C. was measured using a viscometer (Brookfield model DV-III+). 
     Thermogravimetric Analysis (TGA): 
     TGA was performed using a thermal analysis system (Seiko Instruments, TG/DTA 6200). A sample with an average weight of 5 mg was placed in a platinum pan and heated to about 40 to 600° C. at a rate of 10° C./min under a nitrogen stream. The beginning of decomposition was defined as the decomposition temperature (T d ). 
     Differential Scanning Calorimetry (DSC): 
     DSC was performed as follows: A liquid nitrogen cooler was connected to a thermal analysis system (Perkin/Elmer Pyris 1), measurement was conducted at a temperature of −150 to 250° C. in a helium stream at 10° C./min, and the resulting phase transition temperature was determined as the melting point. In the case of a melting point above room temperature, a melting phenomenon was visually observed at around the measurement temperature. 
     Synthesis 
     All of the raw materials used were commercially available, and used in unpurified form. The syntheses of compounds were performed according to the methods described in Reference Documents 1 to 3. 
     Synthesis of K[CF 3 SO 2 NH] 
     A solution of KO t Bu (36.9 g, 0.33 mol) in anhydrous MeOH (150 ml) was added dropwise to a stirred solution of CF 3 SO 2 NH 2  (49.3 g, 0.33 mol) in anhydrous MeOH (250 ml). The reaction mixture was stirred at 50° C. for 2 hours. The stirred mixture was evaporated for 24 hours at 0.02 Torr to give a white solid (60.53 g, 96.4%). 
       19 F NMR (D 2 O, CFCl 3 , 470.6 MHz) δ −78.0 (s, 3F); MS m/z (%) 149 (100) [CF 3 SO 2 NH] − ; Anal. Calcd. for CF 3 O 2 SNK: C, 6.4; H, 0.5; N, 7.5; Found: C, 6.3; H, 0.7; N, 7.7. 
     Synthesis of K[CF 3 SO 2 NSO 2 F] 
     (FSO 2 ) 2 O 1) ) (69.5 g, 0.38 mol) was added dropwise to a stirred solution of K[CF 3 SO 2 NH] (60.0 g, 0.32 mol) in anhydrous Et 2 O (980 ml) over a period of 30 minutes at −20° C. 
     The mixture was stirred for 3 hours at −20° C., and filtered. 
     The crude product (21.5 g) was washed with MeOH and filtered. After removing the solvent under vacuum, the residue was recrystallized from acetone/CHCl 3  to give a product. 
       19 F NMR (CD 3 OD, CFCl 3 , 470.6 MHz) δ 56.8 (s, 1F), −78.0 (s, 3F); MS m/z (%) 230 (100) [CF 3 SO 2 NSO 2 F] − ; Anal. Calcd. for CF 4 O 4 S 2 NK: C, 4.5; N, 5.2; Found: C, 4.3; N, 5.4. 
     Equimolar amounts of the thus-obtained potassium salt of FTA and each of various ammonium bromides were mixed, and unwanted FTA ionic liquid in the resulting water was extracted with dichloromethane. After washing the extracted product with water several times, the dichloromethane was distilled off to give an ionic liquid. 
     DEME[FTA] (0.65 g, 80.3%) 
       1 H NMR (CD 3 OD, TMS, 500.2 MHz) δ 1.33 (m, 6H), 3.04 (s, 3H), 3.38 (s, 3H), 3.43 (q, J=7.3 Hz, 4H), 3.51 (t, J=4.5 Hz, 2H), 3.78 (m, 2H);  19 F NMR (CD 3 OD, CFCl 3 , 470.6 MHz) δ 56.6 (s, F), −78.2 (s, 3F); MS m/z (%) 146 (100) [DEME], 230 (100) [FTA] − ; A nal. Calcd. for C 9 H 20 N 2 F 4 O 5 S 2 : C, 28.7; H, 5.4; N, 7.4; F, 20.2; Found: C, 28.8; H, 5.1; N, 7.5; F, 20.2. 
     PP13[FTA] (2.30 g, 88.2%) 
       1 H NMR (CD 3 OD, TMS, 500.2 MHz) δ 1.02 (t, J=7.3 Hz, 3H), 1.62-1.76 (m, 2H), 1.77-1.84 (m, 2H), 1.90 (m, 4H), 3.04 (s, 3H), 3.27-3.31 (m, 2H), 3.35 (t, J=5.8 Hz, 4H);  19 F NMR (CD 3 OD, CFCl 3 , 470.6 MHz) δ 56.9 (s, F), −78.1 (s, 3F); MS m/z (%) 142 (100) [PP13] + , 230 (100) [FTA] − ; Anal. Calcd. for C 10 H 20 N 2 F 4 O 4 S 2 : C, 32.3; H, 5.4; N, 7.5; F, 20.4; Found: C, 32.4; H, 5.2; N, 7.6; F, 20.4. 
     N1111[FTA] 
     N1111Br (0.54 g, 3.5 mmol) was added to a stirred solution of K[CF 3 SO 2 NSO 2 F] (0.94 g, 3.5 mmol) in CH 3 CN (10 ml) at room temperature. The mixture was stirred for another 3 hours. After distilling off the solvent, the white solid was dissolved in CH 2 Cl 2 , followed by filtration. The solvent was removed under vacuum. The resulting liquid was dried at 80° C. for 24 hours at 0.02 Torr (1.06 g, 99.5%). 
       1 H NMR (CD 3 OD, TMS, 500.2 MHz) δ 3.19 (s, 12H);  19 F NMR (CD 3 OD, CFCl 3 , 470.6 MHz) δ 56.6 (s, F), −78.2 (s, 3F); MS m/z (%) 74 (100) [N1111] + , 230 (100) [FTA] − ; Anal. Calcd. for C 5 H 12 N 2 F 4 O 1 S 2 : C, 19.7; H, 4.0; N, 9.2; F, 25.0; Found: C, 19.9; H, 3.9; N, 9.3; F, 24.8. 
     N2221[FTA] 
     MS m/z (%) 116 (100) [N2221] + , 230 (100) [FTA] − ; Anal. Calcd. for C 8 H 18 N 2 F 4 O 4 S 2 : C, 27.7; H, 5.2; N, 8.1; F, 21.9; Found: C, 27.8; H, 5.2; N, 8.2; F, 21.9. 
     N1112[FTA] (0.51 g, 22.3%) 
       1 H NMR (CD 3 OD, TMS, 500.2 MHz) δ 1.39 (t, J=7.5 Hz, 3H), 3.10 (s, 9H), 3.41 (q, J=7.2 Hz, 2H);  19 F NMR (CD 3 OD, CFCl 3 , 470.6 MHz) δ 56.6 (s, F), −78.1 (s, 3F); MS m/z (%) 88 (100) [N1112] + , 230 (100) [FTA]; Anal. Calcd. for C 6 H 14 N 2 F 4 O 4 S 2 : C, 22.6; H, 4.4; N, 8.8; F, 23.9; Found: C, 22.4; H, 4.4; N, 8.9; F, 24.0. 
     N1113[FTA] (1.46 g, 62.9%) 
       1 H NMR (CD 3 OD, TMS, 500.2 MHz) δ 1.02 (t, J=7.3 Hz, 3H), 1.78-1.86 (m, 2H), 3.12 (s, 9H), 3.26-3.32 (m, 2H);  19 F NMR (CD 3 OD, CFCl 3 , 470.6 MHz) δ 56.8 (s, F), −78.1 (s, 3F); MS m/z (%) 102 (100) [N1113] + , 230 (100) [CF 3 SO 2 NSO 2 F] − ; Anal. Calcd. for C 7 H 16 N 2 F 4 O 4 S 2 : C, 25.3; H, 4.9; N, 8.4; F, 22.9; Found: C, 25.5; H, 4.8; N, 8.5; F, 22.7. 
     N2222[FTA] (2.13 g, 84.4%) 
       1 H NMR (CD 3 OD, TMS, 500.2 MHz) δ 1.29 (t, J=7.5 Hz, 12H), 3.29 (q, J=7.2 Hz, 8H);  19 F NMR (CD 3 OD, CFCl 3 , 470.6 MHz) δ 56.7 (s, F), −78.1 (s, 3F); MS m/z (%) 130 (100) [N2222] + , 230 (100) [FTA]; Anal. Calcd. for C 9 H 20 N 2 F 4 O 4 S 2 : C, 30.0; H, 5.6; N, 7.8; F, 21.1; Found: C, 29.8; H, 5.5; N, 7.8; F, 21.1. 
     P2222[FTA] (2.38 g, 90.1%) 
       1 H NMR (CD 3 OD, TMS, 500.2 MHz) δ 1.22-1.28 (m, 12H), 2.21-2.28 (m, 8H);  19 F NMR (CD 3 OD, CFCl 3 , 470.6 MHz) δ 56.6 (s, F), −78.1 (s, 3F); MS m/z (%) 147 (100) [P2222] + , 230 (100) [FTA] − ; Anal. Calcd. for C 9 H 20 NPF 4 O 4 S 2 : C, 28.7; H, 5.3; N, 3.7; F, 20.1; Found: C, 28.7; H, 5.2; N, 3.7; F, 19.7. 
     Comparative Example 1 
     Compounds corresponding to those obtained in Example 1 were synthesized in the same manner as above, except that TFSA or FSA was used instead of FTA. 
     Comparative Example 2 
     An ionic liquid consisting of a salt of FTA and EMI (1-ethyl-3-methylimidazolium) was prepared in the same manner as above. 
     Example 2 
     The ionic liquids shown below were produced. All of the raw materials used were commercially available, and used in unpurified form. The syntheses of the compounds were performed according to the method described in Reference Document 1-7. 
     Py13[FTA] (2.17 g, 86.5%) 
       1 H NMR (CD 3 OD, TMS, 500.2 MHz) δ 1.02 (t, J=7.3 Hz, 3H), 1.80-1.87 (m, 2H), 2.22 (s 4H), 3.05 (s, 3H), 3.28-3.32 (m, 2H), 3.47-3.56 (m, 4H);  19 F NMR (CD 3 OD, CFCl 3 , 470.6 MHz) δ 56.8 (s, F), −78.1 (s, 3F); MS m/z (%) 128 (100) [Py13] + , 230 (100) [CF 3 SO 2 N SO 2 F] − ; Anal. Calcd. for C 9 H 18 N 2 F 4 O 4 S 2 : C, 30.2; H, 5.1; N, 7.8; F, 21.2; Found: C, 30.1; H, 4.9; N, 7.7; F, 21.2. 
     DEME[FSA] 
     MS m/z (%) 146 (100) [DEME] + , 180 (100) [FSA] − ; Anal. Calcd. for C 8 H 20 N 2 F 2 O 5 S 2 : C, 29.4; H, 6.2; N, 8.6; F, 11.6; Found: C, 29.4; H, 6.2; N, 8.5; F, 11.6. 
     N2221[FSA] 
     MS m/z (%) 116 (100) [N2221] + , 180 (100) [FSA] − ; Anal. Calcd. for C 7 H 18 N 2 F 2 O 4 S 2 : C, 28.4; H, 6.1; N, 9.5; F, 12.8; Found: C, 28.2; H, 6.0; N, 9.4; F, 12.7. 
     N1113[FSA] 
     MS m/z (%) 102 (100) [N1113] + , 180 (100) [FSA] − ; Anal. Calcd. for C 6 H 16 N 2 F 2 O 4 S 2 : C, 25.5; H, 5.7; N, 9.9; F, 13.5; Found: C, 25.5; H, 5.6; N, 10.0; F, 13.5. 
     N1112[FSA] 
     MS m/z (%) 88 (100) [N1112] + , 180 (100) [FSA] − ; Anal. Calcd. for C 5 H 14 N 2 F 2 O 4 S 2 : C, 22.4; H, 5.3; N, 10.4; F, 14.2; Found: C, 22.3; H, 5.2; N, 10.4; F, 14.0. 
     N2222[FSA] 
     MS m/z (%) 130 (100) [N2222] + , 180 (100) [FSA] − ; Anal. Calcd. for C 8 H 20 N 2 F 2 O 4 S 2 : C, 31.0; H, 6.5; N, 9.0; F, 12.2; Found: C, 30.8; H, 6.4; N, 9.0; F, 12.2. 
     N1111[FSA] 
     MS m/z (%) 74 (100) [N1111] + , 180 (100) [FSA] − ; Anal. Calcd. for C 4 H 12 N 2 F 2 O 4 S 2 : C, 18.9; H, 4.8; N, 11.0; F, 14.9; Found: C, 18.8; H, 4.7; N, 11.0; F, 14.9. 
     P2222[TFSA] 
     MS m/z (%) 147 (100) [P2222] + , 280 (100) [TFSA] − ; Anal. Calcd. for C 10 H 20 NPF 6 O 4 S 2 : C, 28.1; H, 4.7; N, 3.3; F, 26.7; Found: C, 28.0; H, 4.6; N, 3.2; F, 25.6. 
     P2222[FSA] 
     MS m/z (%) 147 (100) [P2222] + , 180 (100) [FSA] − ; Anal. Calcd. for C 8 H 20 NPF 2 O 4 S 2 : C, 29.4; H, 6.2; N, 4.3; F, 11.6; Found: C, 29.2; H, 6.1; N, 4.1; F, 11.4. 
     PP14[FTA] 
     MS m/z (%) 156 (100) [PP14] + , 230 (100) [CF 3 SO 2 NSO 2 F] − ; Anal. Ca lcd. for C 11 H 22 N 2 F 4 O 4 S 2 : C, 34.2; H, 5.7; N, 7.3; F, 19.7; Found: C, 33.9; H, 5.7; N, 7.1; F, 19.7. 
     PP14[FSA] 
     MS m/z (%) 156 (100) [PP14] + , 180 (100) [FSA] − ; Anal. Calcd. for C 10 H 22 N 2 F 2 O 4 S 2 : C, 35.7; H, 6.6; N, 8.3; F, 11.3; Found: C, 35.6; H, 6.6; N, 8.3; F, 11.4. 
     PP14[TFSA] 
     MS m/z (%) 156 (100) [PP14] + , 280 (100) [TFSA]; Anal. Calcd. for C 12 H 22 N 2 F 6 O 4 S 2 : C, 33.02; H, 5.08; N, 6.42; F, 26.12; Found: C, 32.7; H, 5.0; N, 6.2; F, 26.3. 
     PP11[FTA] 
     MS m/z (%) 114 (100) [PP11] + , 230 (100) [FTA] − ; Anal. Calcd. for C 8 H 16 N 2 F 4 O 4 S 2 : C, 27.9; H, 4.7; N, 8.1; F, 22.1; Found: C, 27.7; H, 4.5; N, 8.2; F, 22.1. 
     PP11[FSA] 
     MS m/z (%) 114 (100) [PP11] + , 180 (100) [FSA]; Anal. Calcd. for C 7 H 16 N2F 2 O 4 S 2 : C, 28.6; H, 5.5; N, 9.5; F, 12.9; Found: C, 28.4; H, 5.3; N, 9.6; F, 12.9. 
     N5555[FSA] 
     MS m/z (%) 298 (100) [N5555] + , 180 (100) [FSA] − ; Anal. Calcd. for C 20 H 44 N 2 F 2 O 4 S 2 : C, 50.2; H, 9.3; N, 5.9; F, 7.9; Found: C, 50.0; H, 9.3; N, 5.8; F, 7.9. 
     N4444[FSA] 
     MS m/z (%) 242 (100) [N4444] + , 180 (100) [FSA] − ; Anal. Calcd. for C 16 H 36 N 2 F 2 O 4 S 2 : C, 45.5; H, 8.6; N, 6.6; F, 9.0; Found: C, 45.2; H, 8.7; N, 6.6; F, 9.1. 
     N3333[FSA] 
     MS m/z (%) 186 (100) [N3333] + , 180 (100) [FSA] − ; Anal. Calcd. for C 12 H 28 N 2 F 2 O 4 S 2 : C, 39.3; H, 7.7; N, 7.6; F, 10.4; Found: C, 39.2; H, 7.5; N, 7.8; F, 10.4. 
     PMI[FSA] 
     MS m/z (%) 125 (100) [PMI], 180 (100) [FSA] − ; Anal. Calcd. for C 7 H 13 N 3 F 2 O 4 S 2 : C, 27.5; H, 4.3; N, 13.8; F, 12.4; Found: C, 27.7; H, 4.2; N, 13.7; F, 12.5. 
     PMI [TFSA] 
     MS m/z (%) 125 (100) [PMI], 280 (100) [TFSA]; Anal. Calcd. for C 9 H 13 N 3 F 6 O 4 S 2 : C, 26.7; H, 3.3; N, 10.4; F, 28.1; Found: C, 26.7; H, 3.2; N, 10.5; F, 27.9. 
     N1224[TFSA] 
     MS m/z (%) 144 (100) [N1224] + , 280 (100) [TFSA] − ; Anal. Calcd. for C 11 H 22 N 2 F 6 O 4 S 2 : C, 31.1; H, 5.2; N, 6.6; F, 26.9; Found: C, 31.0; H, 5.0; N, 6.6; F, 26.9. 
     DMI[TFSA] 
     MS m/z (%) 97 (100) [DMI] + , 280 (100) [TFSA] − ; Anal. Calcd. for C 7 H 9 N 3 F 6 O 4 S 2 : C, 22.3; H, 2.4; N, 11.1; F, 30.2; Found: C, 22.1; H, 2.5; N, 11.4; F, 30.0. 
     DMI[FSA] 
     MS m/z (%) 97 (100) [DMI] + , 180 (100) [FSA] − ; Anal. Calcd. for C 5 H 9 N 3 F 2 O 4 S 2 : C, 21.7; H, 3.3; N, 15.2; F, 13.7; Found: C, 21.7; H, 3.3; N, 15.2; F, 13.7. 
     N1224[FSA] 
     MS m/z (%) 144 (100) [N1224] + , 280 (100) [TFSA] − ; Anal. Calcd. for C 9 H 22 N 2 F 2 O 4 S 2 : C, 33.3; H, 6.8; N, 8.6; F, 11.7; Found: C, 33.3; H, 6.6; N, 8.8; F, 11.9. 
     N1133[FSA] 
     MS m/z (%) 130 (100) [N1133] + , 180 (100) [FSA] − ; Anal. Calcd. for C 8 H 20 N 2 F 2 O 4 S 2 : C, 31.0; H, 6.5; N, 9.0; F, 12.2; Found: C, 30.7; H, 6.2; N, 9.0; F, 12.2. 
     N1133[TFSA] 
     MS m/z (%) 130 (100) [N1133] + , 280 (100) [FSA] − ; Anal. Calcd. for C 10 H 20 N 2 F 6 O 4 S 2 : C, 29.3; H, 4.9; N, 6.8; F, 27.8; Found: C, 29.1; H, 4.6; N, 6.8; F, 27.6. 
     N1224[FTA] 
     MS m/z (%) 144 (100) [N1224] + , 230 (100) [FTA] − ; Anal. Calcd. for C 10 H 22 N 2 F 4 O 4 S 2 : C, 32.1; H, 5.9; N, 7.5; F, 20.3; Found: C, 32.2; H, 5.7; N, 7.6; F, 20.3. 
     N3333[FTA] 
     MS m/z (%) 186 (100) [N3333] + , 230 (100) [FTA] − ; Anal. Calcd. for C 13 H 28 N 2 F 4 O 4 S 2 : C, 37.5; H, 6.8; N, 6.7; F, 18.3; Found: C, 37.4; H, 6.5; N, 6.8; F, 18.3. 
     N4444[FTA] 
     MS m/z (%) 242 (100) [N4444] + , 230 (100) [FTA] − ; Anal. Calcd. for C 17 H 36 N 2 F 4 O 4 S 2 : C, 43.2; H, 7.7; N, 5.9; F, 16.1; Found: C, 43.3; H, 7.5; N, 6.0; F, 15.9. 
     N5555[FTA] 
     MS m/z (%) 296 (100) [N5555] − , 230 (100) [FTA] − ; Anal. Calcd. for C 21 H 44 N 2 F 4 O 4 S 2 : C, 47.7; H, 8.4; N, 5.3; F, 14.4; Found: C, 47.3; H, 8.5; N, 5.3; F, 14.2. 
     PP12[FSA] 
     MS m/z (%) 128 (100) [PP12] + , 180 (100) [FSA]; Anal. Calcd. for C 8 H 16 N 2 F 2 O 4 S 2 : C, 31.2; H, 5.9; N, 9.1; F, 12.3; Found: C, 30.9; H, 5.6; N, 9.1; F, 12.3. 
     Py12[FTA] 
     MS m/z (%) 114 (100) [Py12] + , 230 (100) [FTA] − ; Anal. Calcd. for C 8 H 16 N 2 F 2 O 4 S 2 : C, 27.9; H, 4.7; N, 8.1; F, 22.1; Found: C, 27.9; H, 4.7; N, 8.3; F, 21.9. 
     Py14[FTA] 
     MS m/z (%) 142 (100) [Py14] + , 230 (100) [FTA] − ; Anal. Calcd. for C 10 H 20 N 2 F 4 O 4 S 2 : C, 32.25; H, 5.41; N, 7.52; F, 20.41; Found: C, 32.11; H, 5.16; N, 7.61; F, 20.43. 
     Py14[FSA] 
     MS m/z (%) 142 (100) [Py14] + , 180 (100) [FSA] − ; Anal. Calcd. for C 9 H 20 N 2 F 2 O 4 S 2 : C, 33.53; H, 6.25; N, 8.69; F, 11.79; Found: C, 33.29; H, 6.00; N, 8.80; F, 11.78. 
     BMI [FTA] 
     MS m/z (%) 139 (100) [BMI] + , 230 (100) [FTA] − ; Anal. Calcd. for C 9 H 15 N 3 F 4 O 4 S 2 : C, 29.3; H, 4.1; N, 11.4; F, 20.6; Found: C, 29.1; H, 4.1; N, 11.4; F, 20.4. 
     PMI[FTA] 
     MS m/z (%) 125 (100) [PMI] + , 230 (100) [FTA] − ; Anal. Calcd. for C 9 H 13 N 3 F 4 O 4 S 2 : C, 27.0; H, 3.7; N, 11.8 F, 21.4; Found: C, 27.1; H, 3.6; N, 11.9; F, 21.3. 
     DMI [FTA] 
     MS m/z (%) 97 (100) [DMI] + , 230 (100) [FTA] − ; Anal. Calcd. for C 6 H 9 N 3 F 4 O 4 S 2 : C, 22.0; H, 2.8; N, 12.8 F, 22.3; Found: C, 22.1; H, 2.8; N, 13.1; F, 23.3. 
     BMI [FTA] 
     MS m/z (%) 139 (100) [BMI] + , 230 (100) [FTA]; Anal. Calcd. for C 9 H 15 N 3 F 4 O 4 S 2 : C, 29.3; H, 4.1; N, 11.4; F, 20.6; Found: C, 29.1; H, 4.1; N, 11.4; F, 20.4. 
     Py12[FSA] 
     MS m/z (%) 114 (100) [Py12] + , 180 (100) [FSA] − ; Anal. Calcd. for C 7 H 16 N2F 2 O 4 S 2 : C, 28.6; H, 5.5; N, 9.5; F, 12.9; Found: C, 28.4; H, 5.3; N, 9.6; F, 12.9. 
     AS44[FTA] 
     MS m/z (%) 126 (100) [AS44] + , 230 (100) [FTA] − ; Anal. Calcd. for C 9 H 16 N 2 F 4 O 4 S 2 : C, 30.3; H, 4.5; N, 7.9; F, 21.3; Found: C, 30.1; H, 4.5; N, 7.7; F, 21.2. 
     AS44[TFSA] 
     MS m/z (%) 126 (100) [AS44] + , 280 (100) [TFSA] − ; Anal. Calcd. for C 10 H 16 N 2 F 6 O 4 S 2 : C, 29.6; H, 4.0; N, 6.9; F, 28.1; Found: C, 29.1; H, 3.9; N, 6.8; F, 28.1. 
     AS44[FSA] 
     MS m/z (%) 126 (100) [AS44] + , 180 (100) [FSA] − ; Anal. Calcd. for C 8 H 16 N 2 F 2 O 4 S 2 : C, 31.4; H, 5.3; N, 9.1; F, 12.4; Found: C, 31.0; H, 9.2; N, 12.4; F, 31.1. 
     PS44[FTA] 
     MS m/z (%) 143 (100) [PS44] + , 230 (100) [FTA] − ; Anal. Calcd. for C 9 H 16 NPF 4 O 4 S 2 : C, 29.0; H, 4.3; N, 3.8; F, 20.0; Found: C, 39.2; H, 4.1; N, 3.9; F, 19.6. 
     PS44[FSA] 
     MS m/z (%) 143 (100) [PS44] + , 180 (100) [FSA] − ; Anal. Calcd. for C 8 H 16 NPF 2 O 4 S 2 : C, 29.7; H, 5.0; N, 4.4; F, 11.8; Found: C, 29.7; H, 4.8; N, 4.3; F, 11.5. 
     PS44 [TFSA] 
     MS m/z (%) 143 (100) [PS44] + , 280 (100) [TFSA] − ; Anal. Calcd. for C 10 H 16 NPF 6 O 4 S 2 : C, 28.4; H, 3.8; N, 3.3; F, 26.5; Found: C, 28.5; H, 3.7; N, 3.4; F, 26.9. 
     Test Example 1 
     Tables 1 to 6 show the melting points, electrical conductivities, glass transition points, thermal decomposition temperatures, viscosities, and densities of the compounds obtained in the Examples and Comparative Examples above. 
     
       
         
           
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                 Melting Point/° C. 
               
            
           
           
               
               
               
               
            
               
                   
                 FTA 
                 FSA 
                 TFSA 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 N1111 
                 117 
                 &gt;300 
                 133 
               
               
                   
                 N1112 
                 63 
                 263 
                 110 
               
               
                   
                 N1113 
                 −28 
                 42 
                 19 
               
               
                   
                 N1122 
                 −13 
                 200 
                 98 
               
               
                   
                 N1133 
                 Tg only 
                 6 
                 39 
               
               
                   
                 N2221 
                 3.6 
                 130 
                 97 
               
               
                   
                 N1224 
                 Tg only 
                 −16 
                 9.4 
               
               
                   
                 DEME 
                 Tg only 
                 −22 
                 Tg only 
               
               
                   
                 N2222 
                 8.5 
                 40 
                 96 
               
               
                   
                 N3333 
                 105 
                 142 
                 106 
               
               
                   
                 N4444 
                 60 
                 99 
                 89 
               
               
                   
                 N5555 
                 18 
                 96 
                 28 
               
               
                   
                 AS44 
                 21 
                 195 
                 114 
               
               
                   
                 PS44 
                 −18.5 
                 67.2 
                 95.9 
               
               
                   
                 DMI 
                 9.9 
                 57 
                 23 
               
               
                   
                 PMI 
                 Tg only 
                 Tg only 
                 Tg only 
               
               
                   
                 BMI 
                 −16.5 
                 Tg only 
                 −2 
               
               
                   
                 P2222 
                 44 
                 73 
                 115 
               
               
                   
                 Py11 
                 118 
                 230 
                 134 
               
               
                   
                 Py12 
                 −12 
                 203 
                 88 
               
               
                   
                 Py14 
                 Tg only 
                 −16 
                 −18 
               
               
                   
                 PP11 
                 95 
                 277 
                 124 
               
               
                   
                 PP12 
                 −8.1 
                 152 
                 86 
               
               
                   
                 PP13 
                 Tg only 
                 3 
                 12 
               
               
                   
                 PP14 
                 Tg only 
                 Tg only 
                 Tg only 
               
               
                   
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 2 
               
             
            
               
                   
               
               
                 Conductivity (25° C.) mS/cm 
               
            
           
           
               
               
               
               
            
               
                   
                 FTA 
                 FSA 
                 TFSA 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 N1111 
                 solid 
                 solid 
                 solid 
               
               
                   
                 N1112 
                 solid 
                 solid 
                 solid 
               
               
                   
                 N1113 
                 5.4 
                 solid 
                 2.9 
               
               
                   
                 N1122 
                 solid 
                 solid 
                 solid 
               
               
                   
                 N1133 
                 3.7 
                 5.6 
                 solid 
               
               
                   
                 N2221 
                 4.3 
                 solid 
                 solid 
               
               
                   
                 N1224 
                 2.8 
                 4.5 
                 1.6 
               
               
                   
                 DEME 
                 4.1 
                 5.6 
                 2.6 
               
               
                   
                 N2222 
                 3.3 
                 solid 
                 solid 
               
               
                   
                 N3333 
                 solid 
                 solid 
                 solid 
               
               
                   
                 N4444 
                 solid 
                 solid 
                 solid 
               
               
                   
                 N5555 
                  0.16 
                 solid 
                  0.15 
               
               
                   
                 AS44 
                 7.0 
                 solid 
                 solid 
               
               
                   
                 PS44 
                 5.0 
                 solid 
                 solid 
               
               
                   
                 DMI 
                 12.1  
                 solid 
                 9.0 
               
               
                   
                 PMI 
                 8.0 
                 10.6  
                 5.5 
               
               
                   
                 BMI 
                 6.0 
                 7.8 
                 4.2 
               
               
                   
                 P2222 
                 solid 
                 solid 
                 solid 
               
               
                   
                 Py11 
                 solid 
                 solid 
                 solid 
               
               
                   
                 Py12 
                 3.4 
                 solid 
                 solid 
               
               
                   
                 Py14 
                 4.6 
                 6.2 
                 2.6 
               
               
                   
                 PP11 
                 solid 
                 solid 
                 solid 
               
               
                   
                 PP12 
                 3.4 
                 solid 
                 solid 
               
               
                   
                 PP13 
                 2.6 
                 3.7 
                 1.5 
               
               
                   
                 PP14 
                 2.1 
                 2.7 
                 1.1 
               
               
                   
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 3 
               
             
            
               
                   
               
               
                 Glass Transition Temperature/° C. 
               
            
           
           
               
               
               
               
            
               
                   
                 FTA 
                 FSA 
                 TFSA 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 N1111 
                 — 
                 — 
                 — 
               
               
                   
                 N1112 
                 — 
                 — 
                 — 
               
               
                   
                 N1113 
                 −103 
                 — 
                 — 
               
               
                   
                 N1122 
                 — 
                 — 
                 — 
               
               
                   
                 N1133 
                 −101 
                 — 
                 — 
               
               
                   
                 N2221 
                 — 
                 — 
                 — 
               
               
                   
                 N1224 
                 −110 
                 −113 
                 −92 
               
               
                   
                 DEME 
                 −107 
                 −112 
                     −94.6 
               
               
                   
                 N2222 
                 — 
                 — 
                 — 
               
               
                   
                 N3333 
                 — 
                 — 
                 — 
               
               
                   
                 N4444 
                 — 
                 — 
                 — 
               
               
                   
                 N5555 
                 — 
                 — 
                 −69 
               
               
                   
                 AS44 
                 — 
                 — 
                 — 
               
               
                   
                 PS44 
                  −93 
                 — 
                 — 
               
               
                   
                 DMI 
                 — 
                 — 
                 — 
               
               
                   
                 PMI 
                 −104 
                 −103 
                 −90 
               
               
                   
                 BMI 
                 −101 
                 −100 
                 −89 
               
               
                   
                 P2222 
                 — 
                 — 
                 — 
               
               
                   
                 Py11 
                 — 
                 — 
                 — 
               
               
                   
                 Py12 
                 — 
                 — 
                 — 
               
               
                   
                 Py14 
                 −106 
                 — 
                 −88 
               
               
                   
                 PP11 
                 — 
                 — 
                 — 
               
               
                   
                 PP12 
                 — 
                 — 
                 — 
               
               
                   
                 PP13 
                  −94 
                 — 
                 — 
               
               
                   
                 PP14 
                  −92 
                  −94 
                 −78 
               
               
                   
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 4 
               
             
            
               
                   
               
               
                 Viscosity (25° C.) cP 
               
            
           
           
               
               
               
               
            
               
                   
                 FTA 
                 FSA 
                 TFSA 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 N1111 
                 solid 
                 solid 
                 solid 
               
               
                   
                 N1112 
                 solid 
                 solid 
                 solid 
               
               
                   
                 N1113 
                 47 
                 solid 
                 82 
               
               
                   
                 N1122 
                 solid 
                 solid 
                 solid 
               
               
                   
                 N1133 
                 64 
                 58 
                 solid 
               
               
                   
                 N2221 
                 57 
                 solid 
                 solid 
               
               
                   
                 N1224 
                 81 
                 80 
                 129 
               
               
                   
                 DEME 
                 53 
                 46 
                 70 
               
               
                   
                 N2222 
                 80 
                 solid 
                 solid 
               
               
                   
                 N3333 
                 solid 
                 solid 
                 solid 
               
               
                   
                 N4444 
                 solid 
                 solid 
                 solid 
               
               
                   
                 N5555 
                 632 
                 solid 
                 554 
               
               
                   
                 AS44 
                 44.0 
                 solid 
                 solid 
               
               
                   
                 PS44 
                 57.1 
                 solid 
                 solid 
               
               
                   
                 DMI 
                 26 
                 solid 
                 39 
               
               
                   
                 PMI 
                 34 
                 30 
                 46 
               
               
                   
                 BMI 
                 38 
                 34 
                 52 
               
               
                   
                 P2222 
                 solid 
                 solid 
                 solid 
               
               
                   
                 Py11 
                 solid 
                 solid 
                 solid 
               
               
                   
                 Py12 
                 77 
                 solid 
                 solid 
               
               
                   
                 Py14 
                 55 
                 56 
                 76 
               
               
                   
                 PP11 
                 solid 
                 solid 
                 solid 
               
               
                   
                 PP12 
                 77 
                 solid 
                 solid 
               
               
                   
                 PP13 
                 96 
                 95 
                 150 
               
               
                   
                 PP14 
                 117 
                 123  
                 182 
               
               
                   
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 5 
               
             
            
               
                   
               
               
                 Thermal Decomposition Temperature/° C. 
               
            
           
           
               
               
               
               
            
               
                   
                 FTA 
                 FSA 
                 TFSA 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 N1111 
                 291 
                 289 
                 420 
               
               
                   
                 N1112 
                 317 
                 331 
                 410 
               
               
                   
                 N1113 
                 326 
                 310 
                 405 
               
               
                   
                 N1122 
                 297 
                 323 
                 407 
               
               
                   
                 N1133 
                 259 
                 292 
                 403 
               
               
                   
                 N2221 
                 314 
                 297 
                 394 
               
               
                   
                 N1224 
                 274 
                 298 
                 398 
               
               
                   
                 DEME 
                 299 
                 293 
                 380 
               
               
                   
                 N2222 
                 305 
                 312 
                 400 
               
               
                   
                 N3333 
                 252 
                 289 
                 376 
               
               
                   
                 N4444 
                 350 
                 292 
                 375 
               
               
                   
                 N5555 
                 354 
                 297 
                 371 
               
               
                   
                 AS44 
                 304 
                 308 
                 437 
               
               
                   
                 PS44 
                 306 
                 333 
                 423 
               
               
                   
                 DMI 
                 306 
                 308 
                 428 
               
               
                   
                 PMI 
                 329 
                 323 
                 416 
               
               
                   
                 BMI 
                 311 
                 272 
                 424 
               
               
                   
                 P2222 
                 350 
                 316 
                 415 
               
               
                   
                 Py11 
                 291 
                 293 
                 414 
               
               
                   
                 Py12 
                 361 
                 294 
                 417 
               
               
                   
                 Py14 
                 370 
                 299 
                 423 
               
               
                   
                 PP11 
                 275 
                 294 
                 421 
               
               
                   
                 PP12 
                 321 
                 313 
                 418 
               
               
                   
                 PP13 
                 366 
                 291 
                 424 
               
               
                   
                 PP14 
                 365 
                 291 
                 420 
               
               
                   
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 6 
               
             
            
               
                   
               
               
                 Density (25° C.)/g/mL 
               
            
           
           
               
               
               
               
            
               
                   
                 FTA 
                 FSA 
                 TFSA 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 N1111 
                 solid 
                 solid 
                 solid 
               
               
                   
                 N1112 
                 solid 
                 solid 
                 solid 
               
               
                   
                 N1113 
                 1.41 
                 solid 
                 1.43 
               
               
                   
                 N1122 
                 solid 
                 solid 
                 solid 
               
               
                   
                 N1133 
                 1.34 
                 1.28 
                 solid 
               
               
                   
                 N2221 
                 1.37 
                 solid 
                 solid 
               
               
                   
                 N1224 
                 1.31 
                 1.24 
                 1.36 
               
               
                   
                 DEME 
                 1.37 
                 1.27 
                 1.42 
               
               
                   
                 N2222 
                 1.38 
                 solid 
                 solid 
               
               
                   
                 N3333 
                 solid 
                 solid 
                 solid 
               
               
                   
                 N4444 
                 solid 
                 solid 
                 solid 
               
               
                   
                 N5555 
                 1.14 
                 solid 
                 1.16 
               
               
                   
                 AS44 
                 1.46 
                 solid 
                 solid 
               
               
                   
                 PS44 
                 1.48 
                 solid 
                 solid 
               
               
                   
                 DMI 
                 1.51 
                 solid 
                 1.56 
               
               
                   
                 PMI 
                 1.38 
                 1.40 
                 1.49 
               
               
                   
                 BMI 
                 1.43 
                 1.33 
                 1.46 
               
               
                   
                 P2222 
                 solid 
                 solid 
                 solid 
               
               
                   
                 Py11 
                 solid 
                 solid 
                 solid 
               
               
                   
                 Py12 
                 1.42 
                 solid 
                 solid 
               
               
                   
                 Py14 
                 1.38 
                 1.32 
                 1.41 
               
               
                   
                 PP11 
                 solid 
                 solid 
                 solid 
               
               
                   
                 PP12 
                 1.42 
                 solid 
                 solid 
               
               
                   
                 PP13 
                 1.39 
                 1.34 
                 1.41 
               
               
                   
                 PP14 
                 1.39 
                 1.30 
                 1.39 
               
               
                   
                   
               
            
           
         
       
     
     Test Example 2 
     Reduction limit potential, oxidation limit potential, and potential window were measured for the various ionic liquids of the Examples and Comparative Examples. The results are shown in Table 7 and  FIG. 1 . The values indicated by “*” in Table 7 were cited from the cited document*:
     Cited document*: Hajime MATSUMOTO et al.,  Journal of Power Sources , Vol. 160, Issue 2 (2006), pp. 1308-1313   

     Measurement Results of Potential Windows 
     25° C. 
     Scan speed: 50 mV/s
 
Working electrode: glassy carbon electrode
 
Counter electrode: platinum
 
Reference electrode:
 
The reference electrode was a platinum wire immersed in an iodine redox containing 60 mM tetrapropylammonium iodide and 15 mM iodine in EMI [TFSI], which was placed in a glass tube sealed with porous vycor glass at its end (the redox potential of ferrocene in each ionic liquid was measured as an internal standard).
 
     Measurement results of potential windows for N2222[FTA], N122.102[FTA], EMI [FTA], and AS44[FTA] are shown in  FIG. 1 . 
     Note that N122.102[FTA] denotes DEME[FTA]. 
     The reduction limit potential and oxidation limit potential shown in Table 7 were measured at 1 mA/cm 2 . 
     
       
         
           
               
               
               
               
               
             
               
                   
                 TABLE 7 
               
               
                   
                   
               
               
                   
                 Reduction 
                 Oxidation 
                   
                   
               
               
                   
                 Limit 
                 Limit 
               
               
                   
                 Potential/V 
                 Potential/V 
                 Potential 
               
               
                   
                 vs Fc/Fc+ 
                 vs Fc/Fc+ 
                 Window/V 
               
               
                   
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
            
               
                 PP13[TFSA] 
                 −3.4 
                 2.5 
                 5.9 
                 * 
               
               
                 PP13[FSA] 
                 −3.2 
                 2.4 
                 5.6 
                 * 
               
               
                 N2222[FTA] 
                 −3.2 
                 2.6 
                 5.8 
               
               
                 N122.1O2[TFSA] 
                 −3.3 
                 2.3 
                 5.6 
               
               
                 N122.1O2[FTA] 
                 −3.2 
                 2.3 
                 5.5 
               
               
                 EMI[TFSA] 
                 −2.5 
                 2.1 
                 4.6 
                 * 
               
               
                 EMI[FSA] 
                 −2.5 
                 2.0 
                 4.5 
                 * 
               
               
                 EMI[FTA] 
                 −2.5 
                 2.0 
                 4.5 
               
               
                   
               
            
           
         
       
     
     These results revealed that the FTA anion exhibits a high electrochemical stability comparable to that of the known TFSA and FSA. 
     In particular, the FTA anion allows the use of N2222 as a cation, and has the most positive oxidation limit potential of the existing amide anions. 
     Test Example 3 
     Li/LiCoO 2  cells were prepared according to the same method as described in Reference Document 8, using ethylene carbonate/dimethyl carbonate (EC/DMC) solutions each containing EMI [FTA], AS44[FTA], or 1M Li—PF 6 . After a rate test, each cell was charged at 4.2 V, and the AC impedance was measured. 
     Moreover, the relationship between discharge capacity and C rate was measured for each of the Li/LiCoO 2  cells prepared using AS44[FTA], EMI [FTA], EMI [FSA], EMI [TFSA], Py13[TFSA], and Py13[FSA]. The measurement results for each cell are shown in  FIGS. 2 and 3 . Lithium electrolytes were prepared by dissolving a lithium salt, Li-TFSA (0.5 M), in the ionic liquids. The cells were constructed based on Reference Document 9. 
     From the results shown in  FIG. 2 , it is observed that the interfacial resistance for EMI-FTA is not very high, even in comparison with that of EC+DMC, and, thus, is relatively low. Further, from the results shown in  FIG. 3 , it is observed that the cell using EMI [FTA] exhibits performance substantially equivalent to that of the cell using EMI [FSA], and that the cell using AS44[FTA] exhibits performance substantially equivalent to that of the cell using Py13[FSA] with a lower viscosity. This confirmed that TFSA enables charging/discharging at 1 C (0.2 mA/cm 2 ) or more, which has not been made possible by using any low-viscosity systems. According to the AC impedance measurement, the FTA-based ionic liquids exhibit low values of apparent interfacial charge transfer resistance, which are close to those of the FSA-based ionic liquids. This indicates that the presence of —FSO 2  groups in the anions causes the interfacial resistance to decrease, which is believed to be a cause of the high rate characteristics. 
     The effects of separator thickness and Li-salt concentration upon the charge/discharge rate characteristics (25° C.) of the Li/LiCoO 2  cell using AS 44  [FTA] were investigated, and cell optimization was performed. As a result, it was observed, as shown in  FIG. 4 , that the cell using AS 44  [FTA] exhibited charge/discharge rate characteristics as high as those of known organic solvent electrolytes. This high performance can be attributed to the following reasons: increasing the lithium salt concentration reduced the interfacial charge transfer resistance at the positive and negative electrodes; and, as shown in  FIG. 5 , while the addition of approximately 1 M lithium salt increased the viscosity of the known TFSA ionic liquid significantly, i.e., seven-fold or more, the viscosities of the FTA ionic liquids did not significantly change, as with the FSA ionic liquid.
     Reference Document 1: S. Kongpricha, W. C. Preusse, R. Schwarer, J. K. Ruff, Inorganic Syntheses, 8, 151-155.   Reference Document 2: Z. B. Zhou, M. Takeda, M. Ue, J Fluorine Chem., 123 (2003), 127-131.   Reference Document 3: Z. B. Zhou, H. Matsumoto, K. Tatsumi, Chem. Eur. J., 10 (2004), 6581-6591.   Reference Document 4: Zhi-bin Zhou, Hajime Matsumoto, Kuniaki Tatsumi, Chem. Eur. J., 11 (2005), 752-766.   Reference Document 5: Zhi-bin Zhou, Hajime Matsumoto, Kuniaki Tatsumi, Chem. Eur. J., 12 (2006), 2196-2212.   Reference Document 6: V. Braun, Chemische Berichte, 49 (1916), 970.   Reference Document 7: N. Ya Derkach, A. V. Kirsanov, Zhurnal Obshchei Khimii, 38 (2) (1968), 331-7.   Reference Document 8: H. Sakaebe et al., Electrochim. Acta, 53 (2007), 1048.   Reference Document 9: H. Sakaebe, H. Matsumoto, Electrochem. Commun., 5 (7) (2003), 594.   

     BRIEF DESCRIPTION OF DRAWINGS 
       FIG. 1  shows a linear sweep voltammogram at 25° C. of N2222[FTA], DEME[FTA], EMI [FTA], and AS44[FTA]. 
       FIG. 2  shows the measurement results of AC impedances (a Cole-Cole plot) of Li/LiCoO 2  cells, each using an electrolyte obtained by adding approximately 0.5 M Li[TFSA] to EMI [FTA] or AS44[FTA], or using an EC/DMC (1:1) solution containing 1 M L 1 -PF 6 ; the AC impedances were determined after subjecting the cells to a rate test, followed by charging at 4.2 V. 
       FIG. 3  shows the relationship between charge/discharge capacity and C rate measured for Li/LiCoO 2  cells prepared using EMI [FTA], AS44[FTA], EMI [FSA], and EMI [TFSA]. 
       FIG. 4  shows the effects of the Li-salt concentration and separator thickness upon the rate characteristics of a Li/LiCoO 2  cell using AS44[FTA] as an electrolyte. 
       FIG. 5  shows the coexisting Li-salt concentration dependencies upon the viscosities of ionic liquids.