1
662
F. Xu et al.
1
3
chromatography analyses (GC) were performed on an
Agilent GC-6890 equipped with a capillary column (ZB-
3.74 (s, 3H), 3.43 (br, 2H), 1.99–1.95 (m, 2H). C NMR
(DMSO, 150 MHz): δ (ppm) 181.27, 157.13, 137.81,
132.04, 128.96, 126.53, 119.90, 114.55, 55.81, 44.34,
6
24, 30 m × 0.32 mm) using a flame ionization detector.
−
1
Thermogravimetric analysis was carried out using an
NETZSCH STA 449F3 simultaneous thermogravimet-
41.89, 30.78. FT-IR (KBr, cm ): 3280, 3199, 3111, 3038,
2996, 2942, 2874, 2835, 1602, 1537, 1510, 1445, 1342,
1296, 1238, 1177, 1104, 1077, 1031, 920, 828, 782, 748,
694, 664, 526. ESI-MS calcd for C H N OS 290.12,
ric analyzer under the N atmosphere in the temperature
2
range from 50 to 600 °C with a heating rate of 10 °C/min.
The DFT calculations were performed with the Gauss-
ian 09 program. The B3LYP/6-311++G(d,p) method has
been used for structure optimizations, and subsequent
frequency calculations at the same level verify the opti-
mized structures to be ground states without imaginary
frequencies (NImag = 0).
1
4
18
4
+
found 291.13 [M+H] .
ILP4. 1-(3-Aminopropyl)imidazole (2.00 g, 16.0 mmol)
and 4-(trifluoromethyl)phenyl isothiocyanate (3.58 g,
1
17.6 mmol) were used. Yield: 4.98 g (95%). H NMR
(DMSO, 600 MHz): δ (ppm) 9.85 (br, 1H), 8.13 (br, 1H),
7.70–7.65 (m, 5H), 7.19 (s, 1H), 6.90 (s, 1H), 4.03 (t,
1
3
2
H), 3.46 (br, 2H), 2.04–2.00 (m, 2H). C NMR (DMSO,
3
.2 Preparation of ILPs and TBILs
150 MHz): δ (ppm) 181.01, 143.79, 137.75, 129.01,
26.25, 125.83, 124.04, 122.44, 119.89, 44.30, 41.79,
1
−
1
By taking ionic liquid precursor ILP1 as an example.
30.41. FT-IR (KBr, cm ): 3161, 3107, 3000, 2960, 2877,
2851, 1614, 1564, 1526, 1437, 1403, 1326, 1311, 1257,
1162, 1108, 1066, 1035, 1012, 917, 840, 737, 644, 625,
599, 568, 514. ESI-MS calcd for C H F N S 328.10,
1
-(3-Aminopropyl)imidazole (2.00 g, 16.0 mmol) was
mixed with 20 mL acetonitrile under an atmosphere of
dry nitrogen. To the stirring solution, phenyl isothiocy-
anate (2.38 g, 17.6 mmol) pre-dissolved in 10 mL acetoni-
trile was added dropwise. The above-mentioned solution
was stirred overnight at room temperature. Slowly a white
precipitate separated, which was collected by filtration
and washed with acetonitrile (3×30 mL). The precipitate
was then dried at 60°C under vacuum overnight to obtain
1
4
15
3
4
+
found 329.11 [M+H] .
Different ionic liquids were prepared by nucleophilic
addition to ionic liquid precursors with bromoethane. By
taking ionic liquid catalyst TBIL1 as an example. Ionic
liquid precursor ILP1 (1.50 g, 5.8 mmol), bromoethane
(1.30 mL, 17.4 mmol), and toluene (20 mL) were poured
in sequence into a 50 mL flask equipped with a magnetic
stirrer and were heated at 80°C for 24 h with vigorous stir-
ring. After the reaction, the reaction mixture was cooled
down to room temperature. The top phase was poured
off, and the solid residue was washed with ethyl acetate
three times. Then, the solid was dried under vacuum at
60°C for 12 h to obtain white solid TBIL1. Yield: 1.91 g
1
white solid ILP1. Yield: 3.95 g (95%). H NMR (DMSO,
6
1
6
00 MHz): δ (ppm) 9.51 (br, 1H), 7.81 (br, 1H), 7.64 (s,
H), 7.39 (d, 2H), 7.32 (t, 2H), 7.19 (s, 1H), 7.11 (t, 1H),
.89 (s, 1H), 4.00 (t, 2H), 3.45 (br, 2H), 2.02–1.98 (m, 2H).
C NMR (DMSO, 150 MHz): δ (ppm) 180.99, 139.62,
37.82, 129.29, 128.99, 124.83, 123.71, 119.91, 44.33,
1
3
1
4
2
1
−1
1.82, 30.65. FT-IR (KBr, cm ): 3330, 3276, 3145–3005,
961, 2939, 1618, 1542, 1500, 1457, 1321, 1268, 1230,
1
(90%). H NMR (DMSO, 600 MHz): δ (ppm) 11.21 (br,
082, 916, 828, 755, 706, 663, 632, 505. ESI-MS calcd for
1H), 9.55 (br, 1H), 9.49 (s, 1H), 7.95 (s, 1H), 7.91 (s, 1H),
7.53–7.51 (m, 2H), 7.46–7.40 (m, 3H), 4.37 (br, 2H), 3.70
+
C H N S 260.11, found 261.12 [M+H] .
1
3
16
4
1
3
ILP2. 1-(3-Aminopropyl)imidazole (2.00 g, 16.0 mmol)
(br, 2H), 3.25 (br, 2H), 2.31 (br, 2H), 1.22 (br, 3H).
C
and p-tolyl isothiocyanate (2.63 g, 17.6 mmol) were used.
NMR (DMSO, 150 MHz): δ (ppm) 167.19, 136.60, 136.08,
129.89, 129.13, 127.95, 122.89, 122.71, 46.90, 44.80,
1
Yield: 4.12 g (94%). H NMR (DMSO, 600 MHz): δ (ppm)
−
1
9
.40 (br, 1H), 7.68 (br, 1H), 7.64 (s, 1H), 7.23 (d, 2H), 7.18
42.24, 27.16, 15.59. FT-IR (KBr, cm ): 3419, 3376, 3139,
3075, 2959, 2864, 2778, 1612, 1587, 1496, 1449, 1303,
1264, 1169, 851, 765, 718, 692, 610, 490. ESI-MS calcd
(
s, 1H), 7.14 (d, 2H), 6.89 (s, 1H), 3.99 (t, 2H), 3.43 (br,
1
3
2
1
1
H), 2.27 (s, 3H), 2.01–1.96 (m, 2H). C NMR (DMSO,
50 MHz): δ (ppm) 181.01, 137.89, 136.85, 134.15,
29.79, 128.96, 124.16, 119.90, 44.34, 41.84, 30.71, 21.02.
+
for C H BrN S 368.07, found 289.16 [M-Br] .
1
5
21
4
TBIL2. Ionic liquid precursor ILP2 (1.50 g, 5.5 mmol),
−1
FT-IR (KBr, cm ): 3342, 3286, 3208, 3167, 3131–3012,
bromoethane (1.23 mL, 16.5 mmol) were used. Yield:
1
2
1
956, 2942, 2927, 1626, 1542, 1517, 1451, 1328, 1268,
1.84 g (88%). H NMR (DMSO, 600 MHz): δ (ppm) 11.09
229, 1082, 920, 821, 762, 664, 628, 505. ESI-MS calcd
(br, 1H), 9.45 (br, 2H), 7.93 (s, 1H), 7.89 (s, 1H), 7.31
(d, 4H), 4.35 (br, 2H), 3.66 (br, 2H), 3.22 (br, 2H), 2.35
+
for C H N S 274.13, found 275.14 [M+H] .
1
4
18
4
1
3
ILP3. 1-(3-Aminopropyl)imidazole (2.00 g, 16.0 mmol)
(s, 3H), 2.28 (br, 2H), 1.21 (br, 3H). C NMR (DMSO,
150 MHz): δ (ppm) 167.29, 138.79, 136.61, 133.49,
130.34, 127.81, 122.91, 122.71, 46.90, 44.80, 42.10, 27.01,
and 4-methoxyphenyl isothiocyanate (2.90 g, 17.6 mmol)
1
were used. Yield: 4.41 g (95%). H NMR (DMSO,
−
1
6
1
00 MHz): δ (ppm) 9.30 (br, 1H), 7.63 (s, 1H), 7.56 (br,
H), 7.21–7.18 (m, 3H), 6.91–6.88 (m, 3H), 3.98 (t, 2H),
21.25, 15.58. FT-IR (KBr, cm ): 3427, 3132, 3065, 2981,
2862, 2818, 1617, 1569, 1509, 1450, 1386, 1302, 1271,
1
3