tetrahydrofurfurylalcohol ( thfa , sigma aldrich,98  % ) , tetrahydrofuran ( thf , sigma aldrich , reagent grade,99  % , bht inhibited ) , sodium metal ( sigma aldrich , reagent grade , dry stick ) , methanesulfonyl chloride ( sigma aldrich , 99.7  % ) , pyridine ( sigma aldrich , anhydrous , 99.8  % ) , and propylene carbonate ( sigma aldrich , anhydrous , 99.7  % ) were purchased and used as received . 1ethyl3methylimidizolium bis(trifluoromethylsulfonyl)imide ( emibti ) , for use in the electrochemical measurements , was synthesized as previously reported.11 elemental analyses were performed independently by atlantic microlabs , inc . , norcross , ga ; intertek pharmaceutical services , whitehouse , nj ; and mhw labs , phoenix , az . the elemental analysis results reported with the synthetic procedures are averages of the results from all three laboratories . electrochemical depositions and cyclic voltammetry were performed by using a pine instruments model afcbp1 potentiostat . conductivity measurements of emibti / bthfe solutions were performed by using a jenway 4590 conductivity meter at 250.3  c . a threeneck roundbottom flask was filled with 200  ml pyridine and 88  ml ( 91.8  g , 0.90  moles ) thfa . the mixture was placed in an ice / water bath and purged with nitrogen for 1  h. methanesulfonyl chloride ( 73  ml , 108.4  g , 0.94  moles ) was added dropwise to the continuously chilled mixture from an addition funnel over a period of 12  h. the mixture was then allowed to warm to room temperature over the next 48  h , at which time it was combined with 500  ml of 1.2  m hcl and extracted three times with 125  ml portions of dichloromethane . the organic phases were combined and then extracted once with 125  ml of 1.2  m hcl , followed by 125  ml of saturated nacl . finally , the dichloromethane solution was dried with mgso4 , and the solvent was removed under reduced pressure . the crude product was a light yellow liquid , and the yield of crude material was 144  g ( 89  % ) . portions of the crude material were vacuum distilled at 0.34  mmhg to obtain pure product ( 125  g , 77  % yield ) , which was a clear , colorless liquid . this material was characterized by using h and c  nmr , 2d nmr , gc caution : ( tetrahydrofuran2yl)methyl methanesulfonateis stable in air at room temperature , but will react violently if heated while exposed to air . h  nmr ( cdcl3 500  mhz ) =1.60 ( m , 1  h ) , 1.8 ( m , 2  h ) , 1.9 ( m , 1  h ) , 3.03 ( s , 3  h ) , 3.76 ( m , 2  h ) , 4.0 ( m , 2  h ) , 4.14  ppm ( m , 1  h ) . c  nmr =76.29 , 71.65 , 68.60 , 37.55 , 27.60 , 25.75  ppm ; elemental analysis : calcd : 39.93  % c , 6.71  % h , 17.79  % s ; found : 40.1  % c , 6.7  % h , 18:01  % s ; gc  ms indicated 98.6  % purity . a twoneck roundbottom flask was filled with 60  ml thf and 20.6  g ( 0.17  moles ) of the sodium salt of thfa , which was prepared by adding sodium metal to excess thfa and collecting the resulting solid . the mixture was placed under a nitrogen flow , heated to approximately 70  c by using an oil bath , and 29  g ( 0.16  moles ) of distilled ( tetrahydrofuran2yl)methyl methanesulfonatewas added dropwise over several hours . then , the temperature of the oil was increased to approximately 170  c , and the thf was allowed to evaporate while the progress of the reaction was monitored by removing small aliquots from the mixture and recording the nmr spectrum . the mixture was allowed to cool to room temperature when the nmr spectrum indicated that the reaction was approximately 90  % complete ( after roughly 48  h ) . diethyl ether ( 100  ml ) was added to the roomtemperature mixture , which was then filtered , and the ether was removed by rotary evaporation . the yield of crude material , which was a browncolored liquid , was 19  g ( 63  % ) . the crude material was purified by vacuum distillation and produced a clear , colorless liquid . the reaction yielded 14  g ( 47  % ) of product that was found to be approximately 99  % pure by gc  ms . h  nmr ( cdcl3 , 500  mhz ) =4.023.93 ( broad m , 2  h ) , 3.813.74 ( m , 2  h ) , 3.703.62 ( m , 2  h ) , 3.483.35 ( m , 4  h ) , 1.911.82 ( broad m , 2  h ) , 1.821.71 ( broad m , 4  h ) , 1.591.47  ppm ( broad m ) ; 13c  nmr ( cdcl3 , 500  mhz ) =77.95 , 77.85 , 74.18 , 74.08 , 68.25 , 28.12 , 28.10 , 25.61 , 25.58  ppm ; elemental analysis : calcd : 64.5  % c , 9.7  % h , 25.8  % o ; found : 64.4  % c , 9.7  % h , 25.9  % o. poly(3,4propylenedioxythiophene ) ( poly(prodot ) ) was potentiodynamically deposited onto 0.5  cm diameter gold disk electrodes from 30  mm solutions of 3,4propylenedioxythiophene in propylene carbonate that contained 100  mm emibti as a supporting electrolyte . the working electrode potential was swept between 1 and + 1.7  v versus ag / ag six times at 100  mv  s to produce the electroactive films . twoelectrode capacitor devices were constructed as previously reported.11 the charge capacity for each electrode was determined by integration of the voltammetric current corresponding to the neutralization of the polymer film on the electrode , and the difference in the capacity for electrodes that were used in a single device was limited to < 10  % . a threeneck roundbottom flask was filled with 200  ml pyridine and 88  ml ( 91.8  g , 0.90  moles ) thfa . the mixture was placed in an ice / water bath and purged with nitrogen for 1  h. methanesulfonyl chloride ( 73  ml , 108.4  g , 0.94  moles ) was added dropwise to the continuously chilled mixture from an addition funnel over a period of 12  h. the mixture was then allowed to warm to room temperature over the next 48  h , at which time it was combined with 500  ml of 1.2  m hcl and extracted three times with 125  ml portions of dichloromethane . the organic phases were combined and then extracted once with 125  ml of 1.2  m hcl , followed by 125  ml of saturated nacl . finally , the dichloromethane solution was dried with mgso4 , and the solvent was removed under reduced pressure . the crude product was a light yellow liquid , and the yield of crude material was 144  g ( 89  % ) . portions of the crude material were vacuum distilled at 0.34  mmhg to obtain pure product ( 125  g , 77  % yield ) , which was a clear , colorless liquid . this material was characterized by using h and c  nmr , 2d nmr , gc caution : ( tetrahydrofuran2yl)methyl methanesulfonateis stable in air at room temperature , but will react violently if heated while exposed to air . h  nmr ( cdcl3 500  mhz ) =1.60 ( m , 1  h ) , 1.8 ( m , 2  h ) , 1.9 ( m , 1  h ) , 3.03 ( s , 3  h ) , 3.76 ( m , 2  h ) , 4.0 ( m , 2  h ) , 4.14  ppm ( m , 1  h ) . c  nmr =76.29 , 71.65 , 68.60 , 37.55 , 27.60 , 25.75  ppm ; elemental analysis : calcd : 39.93  % c , 6.71  % h , 17.79  % s ; found : 40.1  % c , 6.7  % h , 18:01  % s ; gc  ms indicated 98.6  % purity . a twoneck roundbottom flask was filled with 60  ml thf and 20.6  g ( 0.17  moles ) of the sodium salt of thfa , which was prepared by adding sodium metal to excess thfa and collecting the resulting solid . the mixture was placed under a nitrogen flow , heated to approximately 70  c by using an oil bath , and 29  g ( 0.16  moles ) of distilled ( tetrahydrofuran2yl)methyl methanesulfonatewas added dropwise over several hours . then , the temperature of the oil was increased to approximately 170  c , and the thf was allowed to evaporate while the progress of the reaction was monitored by removing small aliquots from the mixture and recording the nmr spectrum . the mixture was allowed to cool to room temperature when the nmr spectrum indicated that the reaction was approximately 90  % complete ( after roughly 48  h ) . diethyl ether ( 100  ml ) was added to the roomtemperature mixture , which was then filtered , and the ether was removed by rotary evaporation . the yield of crude material , which was a browncolored liquid , was 19  g ( 63  % ) . the crude material was purified by vacuum distillation and produced a clear , colorless liquid . the reaction yielded 14  g ( 47  % ) of product that was found to be approximately 99  % pure by gc h  nmr ( cdcl3 , 500  mhz ) =4.023.93 ( broad m , 2  h ) , 3.813.74 ( m , 2  h ) , 3.703.62 ( m , 2  h ) , 3.483.35 ( m , 4  h ) , 1.911.82 ( broad m , 2  h ) , 1.821.71 ( broad m , 4  h ) , 1.591.47  ppm ( broad m ) ; 13c  nmr ( cdcl3 , 500  mhz ) =77.95 , 77.85 , 74.18 , 74.08 , 68.25 , 28.12 , 28.10 , 25.61 , 25.58  ppm ; elemental analysis : calcd : 64.5  % c , 9.7  % h , 25.8  % o ; found : 64.4  % c , 9.7  % h , 25.9  % o. poly(3,4propylenedioxythiophene ) ( poly(prodot ) ) was potentiodynamically deposited onto 0.5  cm diameter gold disk electrodes from 30  mm solutions of 3,4propylenedioxythiophene in propylene carbonate that contained 100  mm emibti as a supporting electrolyte . the working electrode potential was swept between 1 and + 1.7  v versus ag / ag six times at 100  mv  s to produce the electroactive films . twoelectrode capacitor devices were constructed as previously reported.11 the charge capacity for each electrode was determined by integration of the voltammetric current corresponding to the neutralization of the polymer film on the electrode , and the difference in the capacity for electrodes that were used in a single device was limited to < 10  % . as a service to our authors and readers , this journal provides supporting information supplied by the authors . such materials are peer reviewed and may be reorganized for online delivery , but are not copyedited or typeset . technical support issues arising from supporting information ( other than missing files ) should be addressed to the authors .
abstractdespite the availability of a large number of alkyl tetrahydrofurfuryl ethers that have a wide range of applications , pure bis(tetrahydrofurfuryl ) ether ( bthfe ) has not been previously synthesized . here , 
 we report the synthesis of bthfe ( consisting of the rr , ss , and meso stereoisomers ) at greater than 99  % purity from tetrahydrofurfuryl alcohol , using ( tetrahydrofuran2yl)methyl methanesulfonate as an intermediate . 
 additionally , we demonstrate that bthfe can be used as a nonvolatile solvent in poly(3,4propylenedioxythiophene)based supercapacitors . 
 supercapacitor devices employing solutions of the ionic liquid 1ethyl3methylimidizolium bis(trifluoromethylsulfonyl)imide in bthfe display similar performances to those prepared by using the neat ionic liquid as an electrolyte , although solutionbased devices exhibit a somewhat higher resistance .