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Supporting Information for:

1,2-Bis[N-(N’-alkylimidazolium)]ethane Salts: a New Class of Organic Ionic Plastic Crystals

Minjae Lee,a U Hyeok Choi,b Sungsool Wi,a Carla Slebodnick,a Ralph H. Colby b and Harry W. Gibson a*

a Department of Chemistry, Virginia Tech, Blacksburg, VA, USA 24061

b Department of Materials Science and Engineering, Penn State University, State College, PA, USA 16802

* E-mail: hwgibson@vt.edu; FAX: 540-231-8517; Tel: 540-231-5902

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Table of Contents

Experimental ............................................................................................................. S5

Figure S1. 400 MHz 1H NMR and 100 MHz 13C NMR spectrum of 1-heptylimidazole (CDCl3,

22 °C). S7

Figure S2. 400 MHz 1H NMR and 100 MHz 13C NMR spectrum of 1,2-bis[N-(N’-

heptylimidazolium)]ethane 2PF6- (8PF6) (CD3CN, 23 °C). S8

Figure S3. 400 MHz 1H NMR and 100 MHz 13C NMR spectrum of 1-octylimidazole (CDCl3, 22

°C). S9

Figure S4. 400 MHz 1H NMR spectrum of 1,2-bis[N-(N’-octylimidazolium)]ethane 2PF6-

(9PF6) (CD3CN, 23 °C). S10

Figure S5. 400 MHz 1H NMR and 100 MHz 13C NMR spectrum of 1-decylmidazole (CDCl3, 22

°C). S11

Figure S6. 400 MHz 1H NMR and 100 MHz 13C NMR spectrum of 1,2-bis[N-(N’-

decylimidazolium)]ethane 2PF6- (10PF6) (CD3CN, 23 °C). S12

Figure S7. Partial HR ESI MS spectrum of 8PF6. [M-2PF6]2+ at m/z 180.1605 (calcd. m/z

180.1621) proves the formation of the imidazolium dication. The peak at m/z 180.6618 is the

M+1 isotopic peak; 25% intensity relative to M, theory: 24%. S13

Figure S8. Partial HR ESI MS spectrum of 9PF6. [M-2PF6]2+ at m/z 194.1805 (calcd. m/z

194.1778) proves the formation of the imidazolium dication. The peak at m/z 194.6819 is the

M+1 isotopic peak; 28% intensity relative to M, theory: 27%. S14

Figure S9. Partial HR ESI MS spectrum of 10PF6. [M-2PF6]2+ at m/z 222.2085 (calcd. m/z

222.2093) proves the formation of the imidazolium dication. The peak at m/z 222.7100 is the

M+1 isotopic peak; 31% intensity relative to M, theory: 31%. S15

Figure 10. DSC diagram of 1PF6 (heating and cooling rate 5 K/min, N2). Only the second

heating and cooling traces are shown in this figure. S16

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Figure 11. DSC diagram of 3BF4 (heating and cooling rate 5 K/min, N2). Only the second

heating and cooling traces are shown in this figure. S16

Figure 12. DSC diagram of 6PF6 (heating and cooling rate 5 K/min, N2). Only the second

heating and cooling traces are shown in this figure. S17

Figure 13. DSC diagram of 8Br (heating and cooling rate 5 K/min, N2). Only the second heating

and cooling traces are shown in this figure. S17

Figure 14. DSC diagram of 8PF6 (heating and cooling rate 5 K/min, N2). Only the second

heating and cooling traces are shown in this figure. S18

Figure 15. DSC diagram of 9Br (heating and cooling rate 5 K/min, N2). Only the second heating

and cooling traces are shown in this figure. S18

Figure 16. DSC diagram of 9PF6 (heating and cooling rate 5 K/min, N2). Only the second

heating and cooling traces are shown in this figure. ......................................................... S19

Figure 17. DSC diagram of 10Br (heating and cooling rate 5 K/min, N2). Only the second

heating and cooling traces are shown in this figure. S19

Figure 18. DSC diagram of 10PF6 (heating and cooling rate 5 K/min, N2). Only the second

heating and cooling traces are shown in this figure. S20

Figure 19. DSC diagram of 11Br (heating and cooling rate 5 K/min, N2). Only the second

heating and cooling traces are shown in this figure. S20

Figure 20. DSC diagram of 11PF6 (heating and cooling rate 5 K/min, N2). Only the second

heating and cooling traces are shown in this figure. S21

Figure 21. Temperature dependence of the ionic DC conductivity of 1PF6. The DSC ing trace is superimposed on the plot. S21

Figure 22. Temperature dependence of the ionic DC conductivity of 8Br. The DSC cooling trace is superimposed on the plot. S22

Figure 23. Temperature dependence of the ionic DC conductivity of 8PF6. The DSC cooling trace is superimposed on the plot. S22

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Figure 24. Temperature dependence of the ionic DC conductivity of 9Br. The DSC cooling trace is superimposed on the plot. S23

Figure 25. Temperature dependence of the ionic DC conductivity of 10Br. The DSC cooling trace is superimposed on the plot. S23

Figure 26. Arrhenius plots: logarithm of ionic DC conductivity vs. inverse absolute temperature for 1PF6, 8Br, 8PF6, 9Br, 9PF6, 10Br, 10PF6, and 11PF6. S24

Reference S24

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Experimental

1-Heptylimidaozle.S1 To a solution of imidazole (2.40, 30 mmol) in NaOH (50%) solution

(2.86 g, 35 mmol), 1-bromoheptane (5.36 g, 30 mmol) and THF (15 mL) were added. The

mixture was refluxed for 3 days. After the mixture had cooled to room temperature, THF was

removed by a rotoevaporator. The residue was extracted with dichloromethane/water 3 times.

The combined organic layer was washed with water and then dried over Na2SO4. The drying

agent was filtered off and the filtrate solution was concentrated. Drying in a vacuum oven gave a

yellow oily product, 4.71 g (94%). 1H NMR (400 MHz, CDCl3, 22 °C): δ 0.88 (t, J=7, 3H), 1.28

(m, 8H), 1.76 (m, 2H), 3.91 (t, J=7, 2H), 6.90 (s, 1H), 7.04 (s, 1H), 7.45 (s, 1H). 13C NMR (100

MHz, CDCl3, 22 °C): 14.0, 22.5, 26.4, 28.7, 31.0, 31.6, 47.0, 118.7, 129.3, 137.0.

1-Octylimidazole.S1 To a solution of imidazole (2.40, 30 mmol) in NaOH (50%) solution

(2.86 g, 35 mmol), 1-bromooctane (5.79 g, 30 mmol) and THF (15 mL) were added. The mixture

was refluxed for 3 days. After the mixture had cooled to room temperature, THF was removed

by a rotoevaporator. The residue was extracted with dichloromethane/water 3 times. The

combined organic layer was washed with water and then dried over Na2SO4. The drying agent

was filtered off and the filtrate solution was concentrated. Drying in a vacuum oven gave a

yellow oily product, 4.70 g (86%). 1H NMR (400 MHz, CDCl3, 22 °C): δ 0.88 (t, J=7, 3H), 1.28

(m, 10H), 1.76 (m, 2H), 3.91 (t, J=7, 2H), 6.90 (s, 1H), 7.04 (s, 1H), 7.45 (s, 1H). 13C NMR (100

MHz, CDCl3, 22 °C): δ 13.0, 21.6, 15.5, 28.0, 28.1, 30.1, 30.8, 46.0, 117.7, 128.3, 136.0.

1-Decylimidzole. S1 To a solution of imidazole (2.40 g, 30 mmol) in NaOH (50%) solution

(2.86 g, 35 mmol), 1-bromodecane (6.63 g, 30 mmol) and THF (15 mL) were added. The

mixture was refluxed for 3 days. After the mixture had cooled to room temperature, THF was

removed by a rotoevaporator. The residue was extracted with dichloromethane/water 3 times.

The combined organic layer was washed with water and then dried over Na2SO4. The drying

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agent was filtered off and the filtrate solution was concentrated. Drying in a vacuum oven gave a

yellow oily product, 6.31 g (98%). 1H NMR (400 MHz, CDCl3, 22 °C): δ 0.88 (t, J=7, 3H), 1.28

(m (br), 14H), 1.76 (m, 2H), 3.91 (t, J=7, 2H), 6.90 (s, 1H), 7.04 (s, 1H), 7.45 (s, 1H). 13C NMR

(100 MHz, CDCl3, 22 °C): δ 14.0, 22.6, 26.4, 29.0, 29.3, 29.4, 31.0, 31.7, 46.9, 118.7, 129.2,

136.9.

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NMR Spectra

NNC7H15

CHCl 3

CH2Cl2

TMS

CDCl 3

Figure S1. 400 MHz 1H NMR and 100 MHz 13C NMR spectrum of 1-heptylimidazole (CDCl3,

22 °C).

Electronic Supplementary Material (ESI) for Journal of Materials ChemistryThis journal is © The Royal Society of Chemistry 2011

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N N C7H15NN (CH2)2

2PF6-

C7H15

Acetone -d6

H2OAcetone -d6

Figure S2. 400 MHz 1H NMR and 100 MHz 13C NMR spectrum of 1,2-bis[N-(N’-

heptylimidazolium)]ethane 2PF6- (8PF6) (CD3CN, 23 °C).

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TMS

CDCl 3

NNC8H17

Figure S3. 400 MHz 1H NMR and 100 MHz 13C NMR spectrum of 1-octylimidazole (CDCl3, 22

°C).

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CD3CN

CD3CN

CD 3CN

H2O

N N C8H1 7NN (CH2)2

2PF6-

C8H1 7

Figure S4. 400 MHz 1H NMR spectrum of 1,2-bis[N-(N’-octylimidazolium)]ethane 2PF6-

(9PF6) (CD3CN, 23 °C).

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TMS

CDCl 3

NNC10H21

CHCl 3CH2Cl2

Figure S5. 400 MHz 1H NMR and 100 MHz 13C NMR spectrum of 1-decylimidazole (CDCl3,

22 °C).

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CD3CN

CD 3CN

N N C10H2 1NN (CH2)2

2PF6-

C1 0H2 1

CD 3CN

H2O

Figure S6. 400 MHz 1H NMR and 100 MHz 13C NMR spectrum of 1,2-bis[N-(N’-

decylimidazolium)]ethane 2PF6- (10PF6) (CD3CN, 23 °C).

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MS Spectra of the Dications

N N C7H15NN (CH2)2C7H15

Figure S7. Partial HR ESI MS spectrum of 8PF6. [M-2PF6]2+ at m/z 180.1605 (calcd. m/z

180.1621) proves the formation of the imidazolium dication. The peak at m/z 180.6618 is the

M+1 isotopic peak; 25% intensity relative to M, theory: 24%.

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N N C8H17NN (CH2)2C8H17

Figure S8. Partial HR ESI MS spectrum of 9PF6. [M-2PF6]2+ at m/z 194.1805 (calcd. m/z

194.1778) proves the formation of the imidazolium dication. The peak at m/z 194.6819 is the

M+1 isotopic peak; 28% intensity relative to M, theory: 27%.

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N N C10H21NN (CH2)2C 10H21

Figure S9. Partial HR ESI MS spectrum of 10PF6. [M-2PF6]2+ at m/z 222.2085 (calcd. m/z

222.2093) proves the formation of the imidazolium dication. The peak at m/z 222.7100 is the

M+1 isotopic peak; 31% intensity relative to M, theory: 31%.

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DSC Diagrams

214.83°C

199.32°C

-4

-3

-2

-1

0

1

2

3

4

He

at

Flo

w (W

/g)

0 50 100 150 200 250

Temperature (°C)

Sample : MLee -II-153 PF6-1Size : 5.1000 mgMethod : Heat /Cool /HeatComment : III-153PF6 bis (Methylimidazolium )ethane 2PF6

DSCFile : C:... \MLee -II-153 PF6-1.001Operator : MLeeRun Date : 2010-06-04 10 :36Instrument : DSC Q 2000 V23.10 Build 79

Exo Down

heating

cooling

2PF6-

N N NN MeM e

Figure 10. DSC diagram of 1PF6 (heating and cooling rate 5 K/min, N2). Only the second

heating and cooling traces are shown in this figure.

94.80°C

35.78°C-0.5

0.0

0.5

1.0

Heat F

low

(W

/g)

-50 0 50 100

Temperature (°C)

Sample : MLee-II-29BF4Size : 5.7000 mgMethod : Heat /Cool /HeatComment : II-29BF4 Bis (BuIm )ethane 2BF 4

DSCFile : C:... \Bisimidazolium \MLee-II-29BF4.002Operator : RGRun Date : 2010-07-04 23 :15Instrument : DSC Q 2000 V23.10 Build 79

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heating

cooling

2BF4-

N N NNC4H9

C4H9

Figure 11. DSC diagram of 3BF4 (heating and cooling rate 5 K/min, N2). Only the second

heating and cooling traces are shown in this figure.

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9.46°C

78.73°C 79.75°C

196.90°C

191.83°C

2.38°C-0.6

-0.4

-0.2

0.0

0.2

0.4

0.6H

eat F

low

(W/g

)

-50 0 50 100 150 200 250

Temperature (°C)

Sample : MLee -I-098 PF6Size : 4.4000 mgMethod : Heat /Cool /Heat

DSCFile : C:... \Bisimidazolium \MLee -I-098 PF6.002Operator : MinjaeRun Date : 2009 -04 -10 10 :21Instrument : DSC Q 2000 V23.10 Build 79

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heating

cooling

2PF6-

N N NN C6H 13C6H13

Figure 12. DSC diagram of 6PF6 (heating and cooling rate 5 K/min, N2). Only the second

heating and cooling traces are shown in this figure.

17.79°C

33.64°C91.43°C 124.13°C

122.41°C87.10°C

15.95°C

24.79°C

-4

-2

0

2

4

He

at

Flo

w (W

/g)

-50 0 50 100 150 200

Temperature (°C)

Sample : MLee -III -038BrSize : 5.9000 mgMethod : Heat /Cool /HeatComment : 1,2-Bis (heptylimidazolium )ethane 2Br

DSCFile : C:... \Bisimidazolium \MLee -III-038Br.001Operator : MinjaeRun Date : 2009 -06-05 12 :24Instrument : DSC Q2000 V23.10 Build 79

Exo Down

heating

cooling

N N C7H15NNC7H15

2Br -

(CH2)2

Figure 13. DSC diagram of 8Br (heating and cooling rate 5 K/min, N2). Only the second heating

and cooling traces are shown in this figure.

Electronic Supplementary Material (ESI) for Journal of Materials ChemistryThis journal is © The Royal Society of Chemistry 2011

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32.96°C

91.22°C

217.17°C

212.31°C88.41°C

25.56°C-2

-1

0

1

2

3H

ea

t F

low

(W/g

)

-50 0 50 100 150 200 250

Temperature (°C)

Sample : MLee -III -038PF6Size : 4.0000 mgMethod : Heat /Cool /HeatComment : 1,2-Bis (heptylimidazolium )ethane 2PF6

DSCFile : C:... \Bisimidazolium \MLee -III-038PF6.001Operator : MinjaeRun Date : 2009 -06-05 09 :55Instrument : DSC Q2000 V23.10 Build 79

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heating

cooling

N N C7H15NNC 7H15

2PF6-

(CH2)2

Figure 14. DSC diagram of 8PF6 (heating and cooling rate 5 K/min, N2). Only the second

heating and cooling traces are shown in this figure.

5.67°C 135.34°C

133.67°C4.65°C

-1.0

-0.5

0.0

0.5

1.0

Heat F

low

(W/g

)

-50 0 50 100 150 200 250

Temperature (°C)

Sample : MLee -III-036 BrSize : 5.7000 mgMethod : Heat /Cool /HeatComment : MLee-III-036Br 1,2-Bis (octylimidazolium )ethane 2Br

DSCFile : C:... \Bisimidazolium \MLee -III-036Br.001Operator : MinjaeRun Date : 2009-05-29 15 :18Instrument : DSC Q 2000 V23.10 Build 79

Exo Down

heating

cooling

2Br-

N N NN C 8H 17C 8H 17

Figure 15. DSC diagram of 9Br (heating and cooling rate 5 K/min, N2). Only the second heating

and cooling traces are shown in this figure.

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44.14°C

69.98°C236.23°C

233.57°C

66.78°C

33.88°C

-4

-2

0

2

4H

ea

t F

low

(W/g

)

-50 0 50 100 150 200 250

Temperature (°C)

Sample : MLee -III-036 PF6Size : 6.1000 mgMethod : Heat /Cool /HeatComment : MLee-III-036PF6 1,2-Bis (octylimidazolium )ethane 2PF6

DSCFile : C:... \Bisimidazolium \MLee -III-036PF6.001Operator : MinjaeRun Date : 2009-05-29 19 :58Instrument : DSC Q 2000 V23.10 Build 79

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heating

cooling

2PF 6-

N N NNC 8H17

C8H 17

Figure 16. DSC diagram of 9PF6 (heating and cooling rate 5 K/min, N2). Only the second

heating and cooling traces are shown in this figure.

32.29°C

130.94°C

128.54°C

30.67°C-1.5

-1.0

-0.5

0.0

0.5

1.0

1.5

Heat F

low

(W/g

)

-50 0 50 100 150 200 250

Temperature (°C)

Sample : MLee -III-037 BrSize : 5.2000 mgMethod : Heat /Cool /HeatComment : MLee-III-037Br 1,2-Bis (decyllimidazolium )ethane 2Br

DSCFile : C:... \Bisimidazolium \MLee -III-037Br.001Operator : MinjaeRun Date : 2009-05-29 22 :22Instrument : DSC Q 2000 V23.10 Build 79

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N N C10H21NNC

10H

21

2Br -

(CH2)2

cooling

heating

Figure 17. DSC diagram of 10Br (heating and cooling rate 5 K/min, N2). Only the second

heating and cooling traces are shown in this figure.

Electronic Supplementary Material (ESI) for Journal of Materials ChemistryThis journal is © The Royal Society of Chemistry 2011

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62.15°C

103.83°C

249.38°C261.04°C

239.96°C

101.97°C47.86°C

-1.0

-0.5

0.0

0.5

1.0

1.5H

eat F

low

(W/g

)

0 50 100 150 200 250 300

Temperature (°C)

Sample : MLee -III-037 PF6Size : 7.3000 mgMethod : Heat /Cool /HeatComment : MLee-III-037PF6 1,2-Bis (decyllimidazolium )ethane 2PF6

DSCFile : C:... \Bisimidazolium \MLee -III-037PF6.002Operator : MinjaeRun Date : 2009-05-30 07 :42Instrument : DSC Q 2000 V23.10 Build 79

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N N C10H 21NNC10H21

2PF6-

(CH2)2

heating

cooling

Figure 18. DSC diagram of 10PF6 (heating and cooling rate 5 K/min, N2). Only the second

heating and cooling traces are shown in this figure.

55.51°C

142.55°C

139.97°C

54.01°C

-4

-2

0

2

4

He

at

Flo

w (W

/g)

-50 0 50 100 150 200 250

Temperature (°C)

Sample : MLee -III-041 BrSize : 5.6000 mgMethod : Heat /Cool /HeatComment : MLee-III-041Br, 1,2-Bis (1-dodecylimidazolium )ethane 2Br-

DSCFile : C:... \Bisimidazolium \MLee -III-041Br.001Operator : MinjaeRun Date : 2009-06-12 12 :50Instrument : DSC Q 2000 V23.10 Build 79

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cooling

heating

N N C12H25NNC12H25

2Br-

(C H2)2

Figure 19. DSC diagram of 11Br (heating and cooling rate 5 K/min, N2). Only the second

heating and cooling traces are shown in this figure.

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247.38°C

107.98°C75.95°C

240.20°C

100.71°C56.53°C-1.0

-0.5

0.0

0.5

1.0H

eat F

low

(W/g

)

0 50 100 150 200 250 300

Temperature (°C)

Sample : MLee -III-041 PF6-1Size : 3.9000 mgMethod : Heat /Cool /HeatComment : Bis (dodecylimidazolium )ethane 2PF 6

DSCFile : C:... \MLee -III-041 PF6-1.001Operator : AMRun Date : 2010-07-29 22 :19Instrument : DSC Q 2000 V23.10 Build 79

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heating

cooling

N N C12H25NNC12H25

2PF6-

(CH2)2

Figure 20. DSC diagram of 11PF6 (heating and cooling rate 5 K/min, N2). Only the second

heating and cooling traces are shown in this figure.

Figure 21. Temperature dependence of the ionic DC conductivity of 1PF6. The DSC heating trace is superimposed on the plot.

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S22

Figure 22. Temperature dependence of the ionic DC conductivity of 8Br. The DSC cooling trace is superimposed on the plot.

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S23

Figure 23. Temperature dependence of the ionic DC conductivity of 8PF6. The DSC cooling trace is superimposed on the plot.

Figure 24. Temperature dependence of the ionic DC conductivity of 9Br. The DSC cooling trace is superimposed on the plot.

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S24

Figure 25. Temperature dependence of the ionic DC conductivity of 10Br. The DSC cooling trace is superimposed on the plot.

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Figure 26. Arrhenius plots: logarithm of ionic DC conductivity vs. inverse absolute temperature

for 1PF6, 8Br, 8PF6, 9Br, 9PF6, 10Br, 10PF6, and 11PF6.

Reference:

S1. S. Khabnadideh, Z. Reazei, A. Khalafi-Nezhad, R. Bahrinajafi, R. Mohamadi, A. A.

Farrokhroz, Bioorg. Med. Chem. Lett. 2003, 13, 2863.

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