C HARACTERIZATION OF IL S

80

Table 4-1 Schematic representation of the relation between cations and anions for the synthesized ILs

Anions

Cations Cl Br DOSS DDS SBA BS TFMS

[CNC₂Bim]      

[CNC2Him]       

[CNC2Oim]       

[CNC2Dim]    

[P6,6,6,14] 

[P_8,8,8,14]  

[P8,8,8,14]  

[P_8,8,8C₁₀P_8,8,8]  

[P8,8,8C6P8,8,8]  

[CNC₂Heim] 

[CNC2Bzim] 

[CNC₂Ayim] 

The ¹H NMR of the synthesized RTILs is shown in Fig A-1 to Fig A-5. The ¹H and ¹³C NMR, FTIR, elemental analysis (% actual % theoratical), water content and halide contents results for the present ILs are as follows:

+

Br^-

N N

N

Fig 4-1 Structure of [C₂CN Bim]Br

[C₂CN Bim]Br; _H(300 MHz; CDCl₃): = 9.24 (s, 1H, N-CH-N), 7.79 (s, 1H, N-CH- CH), 7.75 (s, 1H, 1H, N-CH-CH), 4.60 (t, 2H, N-CH2- (CH2)2- CH3), 4.29 (t, 2H, 2H, N-CH2-CH2- CN), 3.21 (t, 2H, N-CH2-CH2- CN ), 1.90 ,(m, 2H, N-CH2-CH2-CH2-), 1.38 (m, 2H, CH2-CH2-CH3), 0.98 (t, 3H, CH2-CH3). ¹³C NMR (75 MHz; CDCl3) = 136.80, 121.54, 120.58, 117.28, 48.22, 42.96, 30.02, 19.08, 17.99. 11.43. FTIR-ATR νmax/cm^–1: 2246 and 1562 (CN), 2923, 2854 and 1461 (C-H).

81

Elemental analysis: % actual C, 46.62; H, 6.01; N, 16.97. C₁₀H₁₆N₃Br % theoratical C, 46.52; H, 6.26; N, 16.28; mass fraction of water 40610^-6.

+

Br^-

N N

N

Fig 4-2 Structure of [C2CN Him]Br

[C2CN Him]Br; H(300 MHz; CDCl3): = 9.77 (s, 1H, N-CH-N), 7.82 (s, 1H, N-CH- CH), 7.26 (s, 1H, 1H, N-CH-CH), 4.49 (t, 2H, N-CH2- (CH2)2- CH3), 3.88 (t, 2H, 2H, N-CH2-CH2- CN), 3.00 (t, 2H, N-CH2-CH2- CN ), 1.48,(m, 2H, N-CH2-CH2-CH2-), ), 0.87 (m, 6H, CH2), 0.43 (t, 3H, CH2-CH3). ¹³C NMR (75 MHz; CDCl3) = 128.87, 120.25, 117.39, 106.71, 53.43, 41.24, 32.97, 30.77. 28.58, 20.15, 16.62, 12.24.

FTIR-ATR νmax/cm^–1: 2245 and 1558 (CN), 2929, 2863 and 1458 (C-H).

Elemental analysis: % actual C, 50.56; H, 6.90; N, 13.98. C12H20N3 Br % theoratical C, 50.35; H, 7.06; N, 14.68; mass fraction of water 38510^-6.

+

Br^-

N N

N

Fig 4-3 Structure of [C2CN Oim]Br

[C2CN Oim]Br; H(300 MHz; CDCl3): = 9.80 (s, 1H, NCHN), 8.05 (s, 1H, CHN), 7.39 (s, 1H, CHN), 4.75 (t, 2H, NCH₂), 4.10 (t, 2H, CNCH₂), 3.24 (t, 2H, CH2CH2CN), 1.72 (t, 2H, CH2CH2N), 1.14 (br, 8H, CH2), 0.68 (t, 3H, CH3CH2). ¹³C NMR (75 MHz; CDCl3) = 130.83, 123.71, 120.73, 107.89, 52.92, 42.57, 33.16, 30.58.

29.13, 26.93, 24.58, 20.63, 17.41, 13.22. FTIR-ATR νmax/cm^–1: 2245 and 1561 (CN), 2925, 2858 and 1458 (C-H).

Elemental analysis: % actual C, 52.20; H, 7.43; N, 12.93; S, 5.41. C14H24N3 Br

% theoratical C, 53.49; H, 7.71; N, 13.37; mass fraction of water 36910^-6. +

Br^-

N N

N

Fig 4-4 Structure of [C2CN Dim]Br

[C2CN Dim]Br; H(300 MHz; CDCl3): = 9.82 (s, 1H, NCHN), 7.88(s, 1H, CHN), 7.27(s, 1H, CHN), 4.54 (t, 2H, NCH₂), 3.92 (t, 2H, CNCH₂), 3.05 (t, 2H,

82

CH₂CH₂CN), 1.54 (t, 2H, CH₂CH₂N), 0.93 (br, 12H, CH₂), 0.47 (t, 3H, CH₃CH₂). ¹³C NMR (75 MHz; CDCl₃) = 137.02, 122.95, 121.13, 116.87, 49.61, 45.9, 31.23, 29.68, 28.21, 23.12, 22.65, 18.97, 13.42. FTIR-ATR νmax/cm^–1: 2244 and 1562 (CN), 2921, 2852 and 1461 (C-H).

Elemental analysis: % actual C, 56.22; H, 8.04; N, 12.59. C16H28N3Br % theoratical C, 56.13; H, 8.26; N, 12.28; mass fraction of water 34110^-6.

+

Cl^-

N N

N

Fig 4-5 Structure of [C₂CN Bim]Cl

[C₂CN Bim]Cl; _H(300 MHz; CDCl₃): = 7.92 (s, 1H, N-CH-N), 7.80 (s, 1H, N-CH- CH), 7.70 (s, 1H, N-CH-CH), 4.61 (t, 2H, N-CH2- (CH2)2- CH3 ), 4.31 (t, 2H, N-CH2- CH2- CN ), 3.22 (t, 2H, N-CH2-CH2- CN), 1.92 ,( m, 2H, N-CH2-CH2-CH2-), 1.37 (m, 2H, CH₂-CH₂-CH₃ ), 0.93 (t, 3H, CH₂-CH₃). FTIR-ATR ν_max/cm^–1: 2252 and 1562 (CN), 2958, 2833 and 1460 (C-H).

Elemental analysis: % actual C, 54.28; H, 10.16; N, 19.31. C₁₀H₁₆N₃Cl % theoratical C, 54.39; H, 10.98; N, 19.03; mass fraction of water 47110^-6.

+

Cl^-

N N

N

Fig 4-6 Structure of [C₂CN Him]Cl

[C₂CN Him]Cl; H(300 MHz; CDCl₃): = 9.60 (s, 1H, N-CH-N), 7.48 (s, 1H, N-CH- CH), 6.83 (s, 1H, N-CH-CH), 4.07 (t, 2H, N-CH2- (CH2)4- CH3 ), 3.67 (t, 2H, N-CH2- CH₂- CN ), 3.45 (t, 2H, N-CH₂-CH₂- CN), 2.60 ( m, 2H, -CH₂-CH₂-CH₃), 2.29 (m, 2H, N-CH₂-CH₂-CH₂- ), 1.08 (m, 2H, N-(CH₂)₂-CH₂-), 0.92 ( m, 2H, - CH₂-CH₂- CH3), 0.61 ( t, 3H, - CH2-CH2- CH3). FTIR-ATR νmax/cm^–1: 2250 and 1562 (CN), 2954, 2858 and 1458 (C-H).

Elemental analysis: % actual C, 59.14; H, 8.03; N, 17.67. C₁₂H₂₀N₃Cl % theoratical C, 59.85; H, 8.39; N, 17.45; mass fraction of water 42810^-6.

83 +

Cl^-

N N

N

Fig 4-7 Structure of [C2CN Oim]Cl

[C2CN Oim]Cl; H(300 MHz; CDCl3): = 9.99 (s, 1H, N-CH-N), 7.90 (s, 1H, N-CH- CH), 7.19 (s, 1H, N-CH-CH), 4.48 (t, 2H, N-CH2-(CH2)6-CH3), 3.85 (t, 2H, N-CH2- CH2-CN ), 3.02 (t, 2H, N-CH2-CH2-CN), 2.98 (m, 2H, N-CH2-CH2-CH2), 1.48 (m, 2H, N-CH2-CH2-CH2- ), 0.87 (m, 2H, N-(CH2)3-CH2-), 0.80 ( m, 6H, - N-(CH2)4- (CH2)3-), 0.48 ( t, 3H, -CH2-CH3). FTIR-ATR νmax/cm^–1: 2246 and 1562 (CN), 2925, 2854 and 1460 (C-H).

Elemental analysis: % actual C, 64.78; H, 6.32; N, 16.53. C14H24N3Cl % theoratical C, 64.48; H, 6.20; N, 16.12; mass fraction of water 45910^-6.

N + N

N

O O S O

O O^-

O O

Fig 4-8 Structure of [C2CN Bim]DOSS

[C₂CN Bim]DOSS; _H(300 MHz; CDCl₃): = 9.95 (s, 1 H, NCHN), 7.80 (s, 1 H, CHN), 7.34 (1 H, s, CHN), 4.71 (t, 1 H, CHSO3), 4.28 (t, 2 H, NCH2), 4.05 (d, 4 H, OCH2CH), 3.98 (t, 2 H, CNCH2), 3.19 (t, 2 H, CH2CH2CN), 1.91 (d, 2 H, COCH2CH), 1.62 (t, 2 H, CH2CH2N), 1.38 (d, 4 H, OCH2CH ), 1.24 (br m, 16 H, CH2), 0.84 (t, 15 H, CH3CH2). ¹³C NMR (75 MHz; CDCl3) = 171.26, 168.56, 136.68, 122.64, 116.67, 67.53, 66.92, 62.06, 48.21, 48.00, 47.78, 47.57, 47.36, 30.21, 28.81, 22.75, 19.15, 13.24, 13.20. FTIR-ATR νmax/cm^–1: 2248 and 1564 (CN), 2929, 2871 and 1460 (C-H), 1213 and 1035 (SO₃), 1730 ( C=O), 1161 (C-O-C).

Elemental analysis: % actual C, 59.89; H, 9.15; N, 6.90; S, 5.41. C₃₀H₅₄N₃O₇S % theoratical C, 59.97; H, 9.06; N, 6.99; S, 5.34; mass fraction of water 19810^-6, mass fraction of bromide 7810^-6.

84

N + N

N

O O S O

O O^-

O O

Fig 4-9 Structure of [C₂CN Him]DOSS

[CNC₂Him]DOSS: H(300 MHz; CDCl₃): = 9.83 (s, 1 H, NCHN), 7.80 (s, 1 H, CHN), 7.30 (s, 1 H, CHN), 4.71 (t, 1 H, CHSO3), 4.25 (t, 2 H, NCH2), 4.16 (d, 4 H, OCH₂CH), 4.01 (t, 2 H, CNCH₂), 3.17 (t, 2 H, CH₂CH₂CN), 2.30 (d, 2 H, COCH₂CH), 1.92 (t, 2 H, CH₂CH₂N), 1.59 (d, 4 H, OCH₂CH ), 1. 28 (br m, 24 H, CH₂), 0.88(t, 15 H, CH₃CH₂). ¹³C NMR (75 MHz; CDCl₃) = 171.44, 169.22, 137.68, 123.22, 121.78, 116.96, 76.70, 67.23, 62.05, 50.27, 45.39, 38.56, 34.24, 31.03, 28.88, 25.87, 22.93, 19.62, 14.00, 10.93, 10.78. FTIR-ATR νmax/cm^–1: 2252 and 1562 (CN), 2929, 2870 and 1460 (C-H), 1213 and 1037 (SO3), 1730 ( C=O), 1159 (C-O- C).

Elemental analysis: % actual C, 61.03; H, 9.41; N, 6.52; S, 5.13. C₃₂H₅₈N₃O₇S

% theoratical C, 61.12; H, 9.30; N, 6.52; S, 5.10; mass fraction of water 21910^-6, mass fraction of bromide 6510^-6.

N + N

N

O O S O

O O^-

O O

Fig 4-10 Structure of [C2CN Oim]DOSS

[C2CN Oim]DOSS: H(300 MHz; CDCl3): = 9.72 (s, 1 H, NCHN), 7.86 (s, 1 H, CHN), 7.33 (s, 1 H, CHN), 4.73 (t, 1 H, CHSO3), 4.24 (t, 2 H, NCH 2), 4.13 (d, 4 H, OCH2CH), 3.98 (t, 2 H, CNCH2), 3.19 (t, 2 H, CH2CH2CN), 3.11 (d, 2 H, COCH2CH), 1.89 (t, 2 H, CH2CH2N), 1.62 (d, 4 H, OCH2CH ), 1. 27 (br m, 24 H, CH2), 0.89 (15 H, t, CH3CH2). ¹³C NMR (75 MHz; CDCl3) = 171.41, 169.31, 137.44, 123.30, 121.88, 117.01, 77.35, 67.95, 61.98, 50.25, 45.34, 38.67, 34.09, 31.65, 28.99, 26.25, 23.63, 22.93, 19.66, 14.03, 10.91, 10.85. FTIR-ATR νmax/cm^–1: 2250 and

85

1564 (CN), 2929, 2860 and 1461 (C-H), 1215 and 1035 (SO3), 1730 (C=O), 1159 (C-O-C).

Elemental analysis: % actual C, 62.18; H, 9.44; N, 6.47; S, 4.82. C34H62N3O7S

% theoratical C, 62.10; H, 9.51; N, 6.47; S, 4.88; mass fraction of water 15210^-6, mass fraction of bromide 6710^-6.

N + N

N

O O S O

O O^-

O O

Fig 4-11 Structure of [C₂CN Dim]DOSS

[C₂CN Dim]DOSS: H(300 MHz; CDCl₃): = 9.62 (s, 1 H, NCHN), 7.88(s, 1 H, CHN), 7.34 (s, 1 H, CHN), 4.72 (t, 1 H, CHSO3), 4.24 (t, 2 H, NCH2), 4.17 (d, 4 H, OCH2CH), 3.96 (t, 2 H, CNCH2), 3.21 (t, 2 H, CH2CH2CN), 2.83 (d, 2 H, COCH₂CH), 1.87 (t, 2 H, CH₂CH₂N), 1.55 (d, 4 H, OCH₂CH ), 1.32 (br m, 28 H, CH₂), 0.88 (15 H, t, CH₃CH₂). ¹³C NMR (75 MHz; CDCl₃) = 171.40, 169.37, 137.32, 123.31, 121.93, 117.05, 68.01, 50.23, 45.32, 38.58, 31.82, 30.03, 29.22, 28.84, 26.26, 23.39, 22.90, 19.67, 13.99, 10.83. FTIR-ATR νmax/cm^–1: 2250 and 1564 (CN), 2925, 2873 and 1460 (C-H), 1223 and 1037 (SO₃), 1731 (C=O), 1159 (C-O-C).

Elemental analysis: % actual C, 63.03; H, 9.65; N, 6.04; S, 4.73. C₃₆H₆₆N₃O₇S

% theoratical C, 63.12; H, 9.71; N, 6.13; S, 4.68; mass fraction of water 18410^-6, mass fraction of bromide 8310^-6.

N + N N

O S O O^-

O

Fig 4-12 Structure of [C2CN Bim]DDS

[C2CN Bim]DDS; H(300 MHz; D2O): = 7.81 (s, 1 H, NCHN), 7.75 (s, 2 H, CHN), 4.79 (t, 2 H, NCH2CH2), 4.70 (t, 2 H, OCH2CH2), 4.39 (t, 2 H, CNCH2), 3.33 (t, 2 H,

86

CH₂CH₂CN), 3.30 (t, 2 H, CH₂CH₂N), 1.98 (t, 2 H, CH₂CH₂O), 1.45 (br m, 20 H, CH₂), 1.01 (t, 6 H, CH₃CH₂). ¹³C NMR (75 MHz; D₂O) = 136.29, 123.32, 122.79, 118.04, 68.45, 49.8386, 45.12, 43.64, 32.23, 31.68, 30.13, 26.16, 22.87, 19.96, 19.59, 19.20, 14.05, 13.25. FTIR-ATR νmax/cm^–1: 2252 and 1564 (CN), 2923, 2865 and 1461 (C-H), 1215 and 1163 (SO3).

Elemental analysis: % actual C, 59.35; H, 9.61; N, 9.49; S, 7.15. C22H42N3O4S

% theoratical C, 59.43; H, 9.52; N, 9.49; S, 7.15; mass fraction of water 17010^-6, mass fraction of bromide 6610^-6.

N + N N

O S O O^-

O

Fig 4-13 Structure of [C2CN Him]DDS

[CNC2Him]DDS: H(300 MHz; D2O): = 9.92 (s, 1 H, NCHN), 7.75 (s, 2 H, CHN), 7.51 (t, 2 H, NCH₂CH₂), 4.57 (t, 2 H, OCH₂CH₂), 4.63 (t, 2 H, CNCH₂), 4.19 (t, 2 H, CH₂CH₂CN), 3.18 (t, 2 H, CH₂CH₂N), 1.93 (t, 2 H, CH₂CH₂O), 1.81 (br m, 4 H, CH2), 1.30 (br m, 20 H, CH2), 0.87 (t, 6 H, CH3CH2). FTIR-ATR νmax/cm^–1: 2250 and 1564 (CN), 2923, 2854 and 1461 (C-H), 1217 and 1163 (SO3).

Elemental analysis: % actual C, 61.09; H, 9.92; N, 8.81; S, 6.73. C24H46N3O4S

% theoratical C, 60.98; H, 9.81; N, 8.89; S, 6.78; mass fraction of water 19810^-6, mass fraction of bromide 8310^-6.

N + N

N

O S O O^-

O

Fig 4-14 Structure of [C₂CN Oim]DDS

[C₂CN Oim]DDS: _H(300 MHz; D₂O): = 7.77 (s, 1 H, NCHN), 7.75 (s, 2 H, CHN), 4.81 (t, 2 H, NCH2CH2), 4.57 (t, 2 H, OCH2CH2), 4.27 (t, 2 H, CNCH2), 3.98 (t, 2 H, CH2CH2CN), 3.18 (t, 2 H, CH2CH2N), 1.93 (t, 2 H, CH2CH2O), 1.63 (br m, 8 H, CH2), 1.32 (br m, 20 H, CH2), 0.89 (t, 6 H, CH3CH2). FTIR-ATR νmax/cm^–1: 2250 and 1564 (CN), 2921, 2852 and 1461 (C-H), 1218 and 1163 (SO3).

87

Elemental analysis: % actual C, 62.45; H, 10.05; N, 8.35; S, 6.36. C₂₆H₅₀N₃O₄S % theoratical C, 62.36; H, 10.06; N, 8.39; S, 6.40; mass fraction of water 13710^-6, mass fraction of bromide 5310^-6.

N

+

N

N

O S O O^-

O

Fig 4-15 Structure of [C₂CN Dim]DDS

[C₂CN Dim]DDS; _H(300 MHz; D₂O): = 7.77 (s, 1 H, NCHN), 7.75 (s, 2 H, CHN), 4.58 (t, 2 H, NCH2CH2), 4.25 (t, 2 H, OCH2CH2), 3.98 (t, 2 H, CNCH2), 3.20 (t, 2 H, CH2CH2CN), 3.17 (t, 2 H, CH2CH2N), 1.90 (t, 2 H, CH2CH2O), 1.36 (br m, 12 H, CH₂), 1.29 (br m, 20 H, CH₂), 0.88 (t, 6 H, CH₃CH₂). ¹³C NMR (75 MHz; D₂O) = 122.96, 122.53, 116.5245, 109.39, 67.84, 48.37, 47.7243, 45.07, 31.74, 29.49, 29.45, 29.23, 28.19, 25.94, 25.66, 22.43, 18.62, 13.17. FTIR-ATR νmax/cm^–1: 2250 and 1564 (CN), 2921, 2872 and 1455 (C-H), 1218 and 1163 (SO3).

Elemental analysis: % actual C, 63.68; H, 10.37; N, 7.98; S, 6.01. C₂₈H₅₄N₃O₄S

% theoratical C, 63.60; H, 10.29; N, 7.95; S, 6.06; mass fraction of water 23510^-6, mass fraction of bromide 6210^-6.

N + N

N

O S OH

O O O^-

Fig 4-16 Structure of [C2CN Him]SBA

[CNC2Him]SBA: H(300 MHz; D2O): = = 9.93 (s, 1 H, NCHN), 8.27 (br, 2 H, C(CH)2SO3), 8.06 (s, 1 H, OH), 7.96 (d, 2 H, C(CH)2COOH), 7.59 (s, 1 H, NCHCHN), 7.53 (s, 1 H, NCHCHN), 4.53 (t, 2 H, NCH2 (CH2)4), 4.16 (t, 2 H, CNCH2CH2), 3.13 (t, 2 H, CH2CH2CN), 1.80, (t, 2 H, NCH2CH2 (CH2)3), 1.21 (br m, 6H, CH2), 0.77 (t, 3 H, CH3CH2). ¹³C NMR (75 MHz; D2O) = 135.79, 132.08, 129.63,

88

129.46, 126.31, 123.14, 122.46, 117.88, 49.99, 44.84, 30.34, 29.08, 25.00, 21.81, 19.33, 13.30. FTIR-ATR νmax/cm^–1: 2250 and 1558 (CN), 2921, 2859 and 1461(C- H), 1158 and 1026 (SO3), 1632 (C=O), 3417 (-OH).

Elemental analysis: % actual C, 55.93, H, 6.45; N, 10.35; S, 7.89. C19H26N3O5S

% theoratical C, 56.00; H, 6.18; N, 10.31; S, 7.87; mass fraction of water 23310^-6, mass fraction of bromide 7410^-6.

N + N

N O

S OH O O O^-

Fig 4-17 Structure of [C2CN Oim]SBA

[C2CN Oim]SBA: H(300 MHz; D2O): = 9.02 (s, 1 H, NCHN), 7.64 (br, 2 H, C(CH)2SO3), 7.85 (s, 1 H, OH), 4.70 (d, 2 H, C(CH)2COOH), 4.57 (s, 1 H, NCHCHN), 3.16 (s, 1 H, NCHCHN), 2.19 (t, 2 H, NCH2 (CH2)4), 1.86 (t, 2 H, CNCH2CH2), 1.25 (t, 2 H, CH2CH2CN), 1.21, (t, 2 H, NCH2CH2 (CH2)3), 1.19 (br m, 6H, CH2), 0.79 (t, 3 H, CH3CH2). ¹³C NMR (75 MHz; D2O) = 135.90, 123.12, 122.55, 117.86, 50.00, 44.89, 31.17, 29.25, 28.40, 25.44, 22.14, 19.42, 13.57. FTIR-ATR ν_max/cm^–1: 2254 and 1562 (CN), 2925, 2854 and 1460 (C-H), 1161 and 1030 (SO₃), 1629 (C=O), 3413 (-OH).

Elemental analysis: % actual C, 57.72; H, 6.99; N, 9.57; S, 7.30. C21H30N3O5S % theoratical C, 57.91; H, 6.71; N, 9.65; S, 7.36; mass fraction of water 14510^-6, mass fraction of bromide 5910^-6.

N + N

N O

S OH O O O^-

Fig 4-18 Structure of [C2CN Dim]SBA

[C2CN Dim]SBA: H(300 MHz; D2O): = 9.03 (s, 1 H, NCHN), 8.29 (br, 2 H, C(CH)2SO3), 7.93 (s, 1 H, OH), 7.62 (d, 2 H, C(CH)2COOH), 7.49 (s, 1 H, NCHCHN), 4.54 (s, 1 H, NCHCHN), 4.11 (t, 2 H, NCH2 (CH2)4), 3.11 (t, 2 H, CNCH2CH2), 2.16 (t, 2 H, CH2CH2CN), 1.67, (t, 2 H, NCH2CH2 (CH2)3), 1.09 (br m,

89

6H, CH₂), 0.76 (t, 3 H, CH₃CH₂). ¹³C NMR (75 MHz; D₂O) = 144.78, 136.01, 132.66, 129.44, 128.44, 122.94, 117.74, 49.79, 44.97, 31.85, 29.27, 28.91, 25.88, 22.56, 19.42, 13.81. FTIR-ATR νmax/cm^–1: 2252 and 1562 (CN), 2923, 2852 and 1458 (C- H), 1218 and 1031 (SO3), 1710 (C=O), 3408 (-OH).

Elemental analysis: % actual C, 59.40; H, 7.25; N, 9.15; S, 6.84. C23H34N3O5S

% theoratical C, 59.59; H, 7.17; N, 9.06; S, 6.92; mass fraction of water 21210^-6, mass fraction of bromide 7410^-6.

N

+

N

N

S O O O^-

Fig 4-19 Structure of [C2CN Bim]BS

[C2CN Bim]BS; H(300 MHz; D2O): = 8.98 (br, 2 H, CHCSO3), 7.78 (s, 1 H, NCHN), 7.63 (s, 1 H, CHN), 7.58 (s, 1 H, CHN), 7.54 (d, 3 H, CHCHCH), 4.57 (t, 2 H, NCH2CH2), 4.23 (t, 2 H, CNCH2CH2), 3.17 (t, 2 H, CH2CH2CN), 1.87 (t, 2 H, CH2CH2N), 1.28 (t, 2H, CH2CH3), 0.83 (t, 3 H, CH3CH2). ¹³C NMR (75 MHz; D2O)

= 135.82, 131.53, 129.04, 125.41, 123.12, 117.93, 50.00, 44.84, 30.38, 29.10, 25.01, 21.82, 19.36, 13.32. FTIR-ATR νmax/cm^–1: 2242 and 1562 (CN), 2963, 2861 and 1460 (C-H), 1184 and 1028 (SO3).

Elemental analysis: % actual C, 57.22; H, 6.54; N, 12.57; S, 9.48. C16H22N3O3S

% theoratical C, 57.12; H, 6.59; N, 12.49; S, 9.53; mass fraction of water 18210^-6, mass fraction of bromide 7310^-6.

N

+

N

N

S O O O^-

Fig 4-20 Structure of [C2CN Him]BS

[CNC2Him] BS: H(300 MHz; D2O): = 8.96 (br, 2 H, CHCSO3), 7.75 (s, 1 H, NCHN), 7.61 (s, 1 H, CHN), 7.57 (s, 1 H, CHN), 7.50 (d, 3 H, CHCHCH), 4.56 (t, 2 H, NCH2CH2), 4.19 (t, 2 H, CNCH2CH2), 3.15 (t, 2 H, CH2CH2CN), 1.84 (t, 2 H,

90

CH₂CH₂N), 1.26 (br m, 6H, CH₂), 0.81 (t, 3 H, CH₃CH₂). ¹³C NMR (75 MHz; D₂O) = 135.83, 129.03, 125.40, 123.17, 123.11, 122.48, 122.43, 117.92, 50.02, 49.99, 44.86, 44.83, 30.35, 29.10, 25.01, 21.81, 19.36, 13.31. FTIR-ATR νmax/cm^–1: 2250 and 1562 (CN), 2927, 2858 and 1458 (C-H), 1190 and 1016 (SO3).

Elemental analysis: % actual C, 51.35, H, 7.14; N, 11.57; S, 8.72. C18H26N3O3S

% theoratical C, 59.31; H, 7.19; N, 11.53; S, 8.80; mass fraction of water 20610^-6, mass fraction of bromide 5210^-6.

N + N N

S O O O^-

Fig 4-21 Structure of [C₂CN Oim]BS

[C2CN Oim]BS: H(300 MHz; D2O): = 9.01 (br, 2 H, CHCSO3), 7.77 (s, 1 H, NCHN), 7.62 (s, 1 H, CHN), 7.39 (s, 1 H, CHN), 7.54 (d, 3 H, CHCHCH), 4.54 (t, 2 H, NCH₂CH₂), 4.20 (t, 2 H, CNCH₂CH₂), 3.13 (t, 2 H, CH₂CH₂CN), 1.86 (t, 2 H, CH₂CH₂N), 1.22 (br m, 6H, CH₂), 0.77 (t, 3 H, CH₃CH₂). ¹³C NMR (75 MHz; D₂O) = 135.92, 128.74, 125.60, 123.06, 122.54, 117.85, 49.96, 44.89, 31.25, 29.31, 28.49, 28.33, 25.52, 22.20, 19.43, 13.62. FTIR-ATR νmax/cm^–1: 2248 and 1562 (CN), 2960, 2871 and 1460 (C-H), 1190 and 1031 (SO3).

Elemental analysis: % actual C, C 61.12; H, 7.78; N, 10.61; S, 8.20. C20H30N3O3S

% theoratical C, 61.20; H, 7.70; N, 10.70; S, 8.17; mass fraction of water 18410^-6, mass fraction of bromide 7110^-6.

N + N

N

F F

F S O O

O^-

Fig 4-22 Structure of [C₂CN Bim]TFMS

[C₂CN Bim]TFMS; _H(300 MHz; D₂O): = 8.94 (s, 1 H, NCHN), 7.61 (s, 1 H, CHN), 7.54 (s, 1 H, CHN), 4.56 (t, 2 H, NCH2CH2), 4.23 (t, 2 H, CNCH2CH2), 3.15 (t, 2 H, CH2CH2CN), 1.85 (t, 2H, CH2CH2N), 1.29 (t, 2 H, CH2CH3), 0.90 (t, 3 H, CH3CH2).

13C NMR (75 MHz; D2O) = 135.73, 123.04, 122.33, 121.34, 117.92, 49.71, 44.80,

91

31.17, 19.24, 18.77, 12.66. FTIR-ATR νmax/cm^–1: 2254 and 1564 (CN), 2964, 2875 and 1460 (C-H), 1249 and 1029 (SO₃), 1226 and 1159 (CF₃).

Elemental analysis: % actual C, 40.29, H, 4.94; N, 12.79; S, 9.73. C11H16F3N3O3S % theoratical C, 40.36; H, 4.93; N, 12.84; S, 9.80; mass fraction of water 17910^-6, mass fraction of bromide 10310^-6.

N + N N

F F

F S O O

O^-

Fig 4-23 Structure of [C2CN Him]TFMS

[CNC2Him] TFMS: H(300 MHz; D2O): = 7.92 (s, 1 H, NCHN), 7.60 (s, 1 H, CHN), 7.56 (s, 1 H, CHN), 4.55 (t, 2 H, NCH2CH2), 4.21 (t, 2 H, CNCH2CH2), 3.14 (t, 2 H, CH2CH2CN), 1.84 (m, 6H, CH2), 1.26 (t, 2 H, CH2CH3), 0.81 (t, 3 H, CH3CH2). ¹³C NMR (75 MHz; D2O) = 181.60, 169.11, 161.62, 137.72, 135.79, 127.34, 123.11, 120.29, 117.89, 115.00, 106.15, 49.98, 44.80, 42.59, 30.33, 24.98, 21.78, 9.27, 13.26, 11.93. FTIR-ATR νmax/cm^–1: 2256 and 1564 (CN), 2933, 2864 and 1458 (C-H), 1249 and 1031 (SO3), 1228 and 1159 (CF3).

Elemental analysis: % actual C, 43.98, H, 5.78; N, 11.70; S, 9.13. C13H20F3N3O3S

% theoratical C, 43.94; H, 5.67; N, 11.82; S, 9.02; mass fraction of water 24310^-6, mass fraction of bromide 9110^-6.

N + N N

F F

F S O O

O^-

Fig 4-24 Structure of [C₂CN Oim]TFMS

[C₂CN Oim]TFMS: H(300 MHz; D₂O): = 8.06 (s, 1 H, NCHN), 7.67 (s, 1 H, CHN), 7.55 (s, 1 H, CHN), 4.42 (t, 2 H, NCH2CH2), 4.18 (t, 2 H, CNCH2CH2), 3.12 (t, 2 H, CH2CH2CN), 1.85 (m, 10H, CH2), 1.21 (m, 2 H, CH2CH3), 0.81 (t, 3 H, CH3CH2). ¹³C NMR (75 MHz; D₂O) = 172.00, 165.62, 157.89, 154.98, 137.03, 135.63, 125.94,

92

122.79, 120.21, 118.43, 114.67, 106.72, 99.17, 91.88, 77.63, 67.27, 49.68, 44.65, 31.28, 28.74, 24.96, 22.11, 19.40, 13.30. FTIR-ATR νmax/cm^–1: 2254 and 1562 (CN), 2927, 2858 and 1460 (C-H), 1249 and 1029 (SO3), 1226 and 1159 (CF3).

Elemental analysis: % actual C, 47.01; H, 6.43; N, 10.89; S, 8.42. C15H24F3N3O3S

% theoratical C, 46.99; H, 6.31; N, 10.96; S, 8.36; mass fraction of water 19710^-6, mass fraction of bromide 6210^-6.

N + N

N

OH

O O S O

O O^-

O O

Fig 4-25 Structure of [C₂CN Heim]DOSS

[C₂CN Heim]DOSS; H(300 MHz; CD₃OD): = 9.18 (s, 1 H, NCHN), 7.77 (s, 1 H, CHN), 7.75 (1 H, s, CHN), 7.01 (t, 1 H, CHSO₃), 4.65 (t, 2 H, NCH₂CH₂OH), 4.30 (t, 2 H, NCH₂CH₂OH), 4.08 (d, 4 H, OCH₂CH(CH₂)₂), 3.95 (t, 2 H, CNCH₂CH₂N), 3.40 (t, 2 H, CNCH₂CH₂N), 3.15 (d, 2 H, COCH(SO₃)CH₂), 3.06 (t, 4 H, CH(CH₂)CH₂CH₂), 1.32 (br m, 15 H, CH_,CH₂), 0.95 (t, 12 H, CH₃CH₂). ¹³C NMR (75 MHz; CD₃OD) = 171.58, 168.80, 137.39, 123.66, 122.67, 116.93, 67.77, 62.36, 60.16, 60.04, 52.54, 45.36, 39.18, 33.91, 30.51, 29.10, 23.74, 23.05, 13.49, 10.42.

FTIR-ATR νmax/cm^–1: 2251 and 1566 (CN), 2921, 2874 and 1458 (C-H), 1220 and 1032 (SO3), 1728 ( C=O), 1156 (C-O-C), 3428 (OH).

Elemental analysis: % actual C, 48.71; H, 10.23; N, 8.39; S, 6.41. C20H49N3O8S

% theoratical C, 48.86; H, 10.04; N, 8.55; S, 6.52; mass fraction of water 28310^-6, mass fraction of bromide 6210^-6.

N + N N

O O S O

O O^-

O O

Fig 4-26 Structure of [C2CN Bzim]DOSS

93

[C2CN Bzim]DOSS; H(300 MHz; CD3OD): = 9.27 (s, 1 H, NCHN), 7.79 (t, 2 H, Ar (CH), 7.72 (t, 2 H, Ar (CH), 7.64 (d, 1 H, Ar (CH), 5.50 (s, 1 H, CHCHN), 5.48 (1 H, s, CHCHN), 7.01 (t, 1 H, CHSO3), 4.60 (t, 2 H, NCH2C6H5), 4.11 (d, 4 H, OCH2CH(CH2)2), 3.33 (t, 2 H, CNCH2CH2N), 3.20 (t, 2 H, CNCH2CH2N), 3.05 (d, 2 H, COCH(SO3)CH2), 1.59 (t, 4 H, CH(CH2)CH2CH2)), 1.32 (br m, 14 H, CH2), 0.91 (t, 12 H, CH3CH2). ¹³C NMR (75 MHz; CD3OD) = 171.59, 168.81, 137.13, 134.30, 129.46, 128.77, 123.21, 116.86, 67.83, 67.21, 62.37, 53.34, 47.61, 39.10, 33.93, 30.38, 29.10, 23.03, 18.87, 13.47, 10.35. FTIR-ATR νmax/cm^–1: 2246 and 1557 (CN), 2928, 2864 and 1460 (C-H), 1220 and 1031 (SO₃), 1726 (C=O), 1152 (C-O- C).

Elemental analysis: % actual C, 62.71; H, 8.26; N, 6.57; S, 5.11. C33H51N3O7S

% theoratical C, 62.53; H, 8.11; N, 6.63; S, 5.06. mass fraction of water 20410^-6, mass fraction of bromide 7810^-6.

N + N

N

O O S O

O O^-

O O

Fig 4-27 Structure of [C2CN Ayim]DOSS

[C2CN Ayim]DOSS; H(300 MHz; CD3OD): = 9.18 (s, 1 H, NCHN), 7.81 (s, 1 H, CHCHN), 7.80 (1 H, s, CHCHN), 7.71 (t, 1 H, N-CH=CH2), 5.48 (t, 1 H, CHSO3), 4.95 (d, 2 H, N-CH=CH2), 4.62 (d, 4 H, OCH2CH(CH2)2), 4.07 (t, 2 H, CNCH2CH2), 3.34 (t, 2 H, CNCH2CH2), 3.23 (d, 2 H, COCH(SO3)CH2), 3.01 (t, 4 H, CH(CH2)CH2CH2), 1.61 (d, 4 H, CH(CH2)CH2CH3), 1.34 (br m, 12 H, CH2), 0.92 (t, 12 H, CH3CH2). ¹³C NMR (75 MHz; CD3OD) = 171.57, 168.85, 137.50, 131.03, 123.76, 121.07, 123.21, 116.97, 67.21, 62.81, 52.01, 48.07, 39.14, 33.94, 30.52, 23.06, 18.91, 13.33, 10.24. FTIR-ATR νmax/cm^–1: 2247 and 1568 (CN), 2926, 2879 and 1461 (C-H), 1223 and 1027 (SO3), 1724 (C=O), 1152 (C-O-C), 1645 (C=C).

Elemental analysis: % actual C, 59.71; H, 8.51; N, 7.44; S, 5.56. C28H47N3O7S

% theoratical C, 59.03; H, 8.31; N, 7.38; S, 5.63 mass fraction of water 22910^-6, mass fraction of bromide 5910^-6.

94 P⁺

Cl^- Fig 4-28 Structure of [P_8,8,8,14]Cl

[P_8,8,8,14]Cl; H(400 MHz; CDCl₃): = 2.36 (t, 8H, CH₂P), 1.65(m, 8H, CH₂CH₂P), 1.23 (br, 52H, CH2), 0.86 (t, 12H, CH3CH2).

Elemental analysis: % actual C, 72.51; H, 12.64. C₃₈H₈₀PCl % theoratical C, 72.36;

H, 12.82. mass fraction of water 38910^-6.

P⁺ P⁺

Cl^- Cl^-

Fig 4-29 Structure of [P8,8,8C6P8,8,8]Cl2

[P_8,8,8C₆P_8,8,8]Cl₂; _H(400 MHz; CDCl₃): = 2.30-2.42 (br, 16H, CH₂CH₂P), 2.1-2.25 ( br, 52H, CH2), 1.35-1.55 (br, 16H, CH2CH2P), 1.21 (m, 12H, CH3CH2), 0.79 (t, 18H, CH3CH2).

Elemental analysis: % actual C, 72.21; H, 12.75. C54H114P2Cl2 % theoratical C, 72.34; H, 12.84 mass fraction of water 53010^-6.

P⁺

P⁺

Cl^- Cl^-

Fig 4-30 Structure of [P8,8,8C10P8,8,8]Cl2

95

[P8,8,8C10P8,8,8]Cl2;H(400 MHz; CDCl3): = 2.25-2.40 (br, 16H, CH2CH2P), 2.0-2.08 (br. 60H, CH₂), 1.30-1.60 (br, 16H, CH₂CH₂P), 1.15 (m, 12H, CH₃CH₂), 0.74 (t, 18H, CH3CH2).

Elemental analysis: % actual C, 73.01; H, 12.85. C58H122P2Cl2 % theoratical C, 73.12; H, 12.93 mass fraction of water 55310^-6.

P⁺

O O

S O O

O^- O

O

Fig 4-31 Structure of [P6,6,6,14]DOSS

[P6,6,6,14]DOSS; H(400 MHz; CDCl3): = 5.10 (s, 1H, CO-CH), 3.90-4.20 (br, 4H, CH2-O), 3.10 (t, 2H, CH2COO), 2.2-2.3 (br, 8H, CH2-P), 1.26-1.41 (br, 64H, CH2), 0.89 (t, 24H, CH3). FTIR-ATR νmax/cm^–1: 2923 and 2854 (C-H), 1230 and 1033 (SO3), 1731 ( C=O), 1159 (C-O-C).

Elemental analysis: % actual C, 68.23; H, 11.57; S, 3.47. C52H115O7PS % theoratical C, 68.98; H, 11.69; S, 3.54 mass fraction of water 12710^-6, mass fraction of chloride 6910^-6.

P⁺

O O

S O O

O^- O

O

Fig 4-32 Structure of [P8,8,8,14]DOSS

[P8,8,8,14]DOSS; H(400 MHz; CDCl3): = 3.96 (s, 1H, CO-CH), 3.25-4.20 (br, 4H, 4H, CH2-O), 2.35 (t, 2H, CH2COO), 1.66 (br, 8H, CH2-P), 1.29 (br, 76H, CH2), 0.88 (t, 24H, CH3). ¹³C NMR (75 MHz; CDCl3) =171.73, 169.13, 77.01, 66.96, 61.92, 38.53, 34.32, 31.73, 30.08, 28.99, 22.59, 21.78, 18.93, 14.02, 10.84. FTIR-ATR

νmax/cm^–1: 2923 and 2854 (C-H), 1220 and 1033 (SO3), 1733( C=O), 1155 (C-O-C).

Elemental analysis: % actual C, 68.65; H, 11.87; S, 3.49. C58H117O7PS % theoratical C, 68.98; H, 11.69; S, 3.54 mass fraction of water 12110^-6, mass fraction of chloride 4110^-6.

96

P⁺ P⁺

O O

S O O

O^- O

O

O O S O

O O^-

O O

Fig 4-33 Structure of [P_8,8,8C₆P_8,8,8]DOSS₂

[P_8,8,8C₆ P_8,8,8]DOSS; H(400 MHz; CDCl₃): = 7.26 (m, 2H, CO-CH), 4.15 (br, 8H, CH₂-O), 3.34 (m, 4H, CH₂COO), 2.76 (t, 16H, CH₂-P), 2.18 (br, 8H, CH₂), 1.25 (br, 108H, CH₂), 0.84 (t, 42H, CH₃). ¹³C NMR (75 MHz; CDCl₃) = 171.66, 169.34, 77.00, 67.10, 38.65, 31.70, 30.26, 28.94, 3.42, 22.58, 21.88, 19.24, 14.01, 10.82. FTIR-ATR νmax/cm^–1: 2923 and 2856(C-H), 1222 and 1033 (SO₃), 1731 (C=O), 1155 (C-O-C).

Elemental analysis: % actual C, 67.73; H, 11.28; S, 3.72. C₉₄H₁₈₈O₁₄P₂S₂ % theoratical C, 67.66; H, 11.36; S, 3.84 mass fraction of water 14210^-6, mass fraction of chloride 5910^-6.

P⁺

P⁺ O

O S

O O

O^- O

O

O O S O

O O^-

O O

Fig 4-34 Structure of [P_8,8,8C₁₀P_8,8,8]DOSS₂

[P_8,8,8C₁₀P_8,8,8]DOSS; H(400 MHz; CDCl₃): = 7.20 (m, 2H, CO-CH), 3.99 (br, 8H, CH₂-O), 3.14 (m, 4H, CH₂COO), 2.22 (t, 16H, CH₂-P), 1.42 (br, 8H, CH₂), 1.19 (br, 116H, CH₂), 0.81 (t, 42H, CH₃). FTIR-ATR νmax/cm^–1: 2925 and 2856 (C-H), 1218 and 1033 (SO₃), 1731 ( C=O), 1157 (C-O-C).

Elemental analysis: % actual C, 68.39; H, 11.59; S, 3.65. C₉₈H₁₉₆O₁₄P₂S₂ % theoratical C, 68.25; H, 11.45; S, 3.72 mass fraction of water 13610^-6, mass fraction of chloride 7410^-6.

97

The imidazolium cation, as for any aromatic system, generates two magnetically shielding cones above and below its molecular plane, classically seen as caused by an electronic current circulating around the -orbitals, on both sides of the aromatic ring.

A proton penetrating into these cones will have an NMR signal moving to higher field. The ¹H NMR spectra of the imidazolium-based ILs showed the C-2 characteristic resonance at high field (7.81-9.99 ppm) due to the acidic proton in the C-2 of imidazolium ring and the other ring protons observed between 6.83-8.29 ppm.

This might be due to the relatively strong electron withdrawing effect of the nitrile group incorporated to the imidazolium ring which increases the acidity of the acidic protons in the C-2 of imidazolium ring and the other protons in the C-4 and C-5.

The most noteworthy feature of the ¹H NMR spectra of the imidazolium salts is the characteristic resonance for the acidic proton in the 2-position. In [C2CN Cnim]X RTILs this proton is observed between 9.24 – 9.82 ppm (for [C2CN Cnim]Br), 7.92- 9.99 ppm (for [C2CN Cnim]Cl), 9.95 – 9.96 ppm (for [C2CN Cnim]DOSS, 7.81 – 7.77 ppm (for [C2CN Cnim]DSS), 9.93 – 9.03 ppm (for [C2CN Cnim]SBA), 8.98 – 9.01 ppm (for [C₂CN C_nim]BS) and 8.94 – 8.06 ppm (for [C₂CN C_nim]TFMS) but no clear trends are present. It is noteworthy that H-D exchange takes place at the acidic 2- position in all the ionic liquids described, and is fastest where the alkyl chain is shortest and the protons interact most strongly with the anion. The chemical shifts of the imidazolium protons in the C-2, C-4 and C-5 are most influenced by such variables as the concentration, structure of the ionic liquid, nature of deuterated solvent and temperature [191].

It is supposed that with concentration increase, the imidazolium cations progressively form ions pairs with the anions, which stack as the neutral aromatic systems do. Thus, the chemical shift displacement with concentration can be analyzed in terms of two effects: H-bonding leading to higher shifts and ring stacking leading to lower shifts. The extreme case is that of the CH3 protons of the ethyl group. Being unable to H-bond, they are only affected by ring stacking. For the other protons, both effects can be observed, depending on the nature of the anion and on its concentration [192]. With the most basic anions, the influence of concentration is in part or completely opposite for protons in the C-2 and C-4 which can be rationalized based

98

on the top-to-bottom structure. It can be assumed that the stacking will take place the closest to that model for the most tightly bound ion-pairs, which means for the most basic anions. With a concentration increase, the proton in the C-2 entering the shielding cone of the neighboring imidazolium moves to lower shifts while the protons in the C-4 and C-5, pointing outside, remain only influenced by H-bonding strengthening [192].

The ionic interactions present in neat ILs will be affected by the addition of molecular solvents. Depending on the dielectric constants of the molecular solvents, more or less effective ion solvation should be observed leading to changes in the NMR spectra of the ionic liquid [193]. The influence of the concentration is more complex. It is expected that a concentration increase will displace the equilibrium to the right and thus lead to a chemical shift increase. This trend is observed for the protons in the C-2 signal only with the most basic anions (DOSS, DDS) and at low concentration [194].

The alkyl protons adjacent to the nitrile group also exchange with deuterium, but at a considerably slower rate. It is possible that the slight differences in the molecular geometry are caused by the different hydrogen bond networks arising from the different anions and different side chains. Hydrogen bonds between the hydrogen bond acceptor usually from the counteranions and the H atoms in the imidazolium ring are the most frequently observed interactions, and in most cases they are the strongest. However, the strength of the hydrogen bond is largely dependent on the nature of the counteranion.

Sulfonate based anions that have strong electron withdrawing groups such as trifluoromethane and carbonyl, hence the C-2 of the imidazolium cation resonate downfield compared to benzene sulfonate and dodecylsulfate. In addition, hydrogen bonding would produce a downfield shift [195]. H-bonding in imidazolium ring depends on the basicity of anion. C-2 proton is less electron rich than C-4 and C-5 because it is attached to carbon in between two electronegative nitrogen atoms. So C- 2 proton is more prone for H-bonding with counter anion than others. Increase in the length of alkyl chain resulted in the different shift between C-4 and C-5 protons [24].

99

The chemical shifts of the imidazolium ring protons are anion- and concentration- dependent [196].

The ¹³C NMR chemical shifts of the carbonyl carbon move to higher field by the hydrogen bonding. The chemical shift of the carbonyl carbon of the [C2CN Bim]DOSS RTILs is 168.56 ppm and the chemical shift was shifted to 169.22, 169.31 and 169.37 ppm for the analogous RTILs incorporating hexyl, octyl and decyl alkyl chains respectively. When the imidazolium cation forms a hydrogen bond the chemical shifts of the ring protons move to a lower field. The decrease of alkyl chain length caused a slight movement of the chemical shift of imidazolium ring protons to the lower field so there is little hydrogen bond formation. This different finding showed that the imidazolium cation formed weaker hydrogen bonding with the carbonyl carbon as the alkyl chain increase. It is well known that hydrogen bonding causes the proton chemical shift to move to lower field. It has also been noticed that the shifts of the imidazolium ring protons depend on the concentration of the solvent used and on the anion.

The FTIR spectra of the present imidazolium-based ILs show the characteristic absorption bands of the nitrile group in the range from 2235 to 2265 cm^-1, exhibit C-H bond at 3080 to 3145 cm^-1 and weaker C-H bonds stretches from 2854 to 2933 cm^-1, which are similar to that reported for other nitrile-functionalized ILs [41, 106, 197]. In addition, characteristic absorption peaks for the -SO₃^- group in the regions from 1180-1250 cm^-1 and 1020-1170 cm^-1 were also observed. The ILs incorporating the DOSS anion showed strong peak at 1710-1730 cm^-1 which is due to the presence of the C=O group. Moreover and as shown in Fig 4-35, the larger the sulfonate based anions, the weaker the CN peak. Allyl and 2-hydroxyethyl imidazolium ILs contains stretches at 3050-3100 cm^-1 and 3428 cm^-1 that correspond to =C─H and OH vibrations respectively while the C=C stretch was observed at 1645 cm^-1. The ILs incorporating the SBA anion show characteristic absorption bands of the OH group at 3405-3420 cm^-1.

The water content value of the present ILs is comparable with the other ILs [16].

Since the present synthesized RTILs incorporating halide anion are highly hygroscopic in nature compared to the other anions their water content was high

100

comparable to the other anions. The water content and halide content of the present ILs are reported along with the characterization results due to their strong effect on the thermophysical properties [100].

Fig 4-35 FTIR spectra of [CNC₂Him]DOSS, [CNC₂Him]DDS, [CNC2Him]BS, [CNC2Him]SBA and [CNC2Him]TFMS