Amino-Functional Imidazolium Ionic Liquids
Fig. 1 Amino-functional
imidazolium ionic liquid
N
N
NH2
N
N
NH2
N
N
NH2
Cl
Br
I
[APmim]Cl
[APmim]Br
[APmim]I
N
N
Cl
NH2
N
N
Cl
NH2
N
N
NH2
I
[APeim]Cl
[APbim]Cl
[APbim]I
chloride ([APbim]Cl) and 1-(3-aminopropyl)-3-butylimi-
dazolium iodide ([APbim]I), were prepared by the similar
way Fig. 1.
were charged into the reactor vessel without using any co-
solvent and co-catalyst. The reactor vessel was placed under
a constant pressure of carbon dioxide and then heated to
120 °C for 1.5 h. Then the reactor was cooled to ambient
temperature, and the resulting mixture was transferred to a
50 ml round bottom flask. By distillation under vacuum, the
product propylene carbonate 2a was then obtained as a col-
orless liquid. The cyclic carbonates were identified on GC–
MS (HP6890/5973) and NMR. The catalyst was separated
from the resulting mixture by distillation under vacuum and
reused directly without further treatment.
All the amino-functional imidazolium ionic liquids were
1
determined by H NMR and FT-IR, and the data was
provided as follows:
1
[
APmim]Cl: H NMR (400 MHz, D O): d (ppm) 7.44
2
(
s, 1H), 7.41 (s, 1H), 4.17 (t, 2H), 3.79 (s, 3H), 2.67 (t, 2H),
1
1
.97 (m, 2H); FT-IR (KBr): 3422, 3151, 3097, 2959, 1625,
1
-
573, 1462, 1339, 1170, 1022, 839, 756, 650, 622 cm
1
.
[
APmim]Br: H NMR (400 MHz, D O): d (ppm) 7.41
2
(
s, 1H), 7.35 (s, 1H), 4.18 (t, 2H), 3.80 (s, 3H), 2.68 (t, 2H),
The NMR characterizations of cyclic carbonates were
shown as follows:
2
1
6
.00 (m, 2H); FT-IR (KBr): 3427, 3153, 3095, 2951, 2857,
639, 1569, 1462, 1383, 1334, 1169, 1111, 1020, 837, 754,
1
4-Methyl-1,3-dioxolan-2-one: H NMR (400 MHZ,
-
1
50, 620 cm
.
CDCl ): d (ppm) 4.84 (m, 1H), 4.54 (dd, 1H), 4.01 (dd,
3
1
13
[
APmim]I: H NMR (400 MHz, D O): d (ppm) 7.42 (s,
1H), 1.47 (d, 3H); C NMR (100 MHz, D2O): d (ppm)
155.05, 73.54, 70.66, 19.42;
2
1
2
1
8
H), 7.37 (s, 1H), 4.19 (t, 2H), 3.81 (s, 3H), 2.68 (t, 2H),
.02 (m, 2H); FT-IR (KBr): 3430, 3146, 3091, 2945, 2871,
625, 1571, 1458, 1386, 1338, 1167, 1109, 1073, 1020,
1
4-(Chloromethyl)-1,3-dioxolan-2-one: H NMR (400
MHZ, CDCl ) d (ppm) 4.97 (mm, 1H), 4.58 (t, 1H), 4.40
3
-
1
13
31, 754, 650, 619 cm
1
.
(dd, 1H), 3.75 (mm, 2H); C NMR (100 MHz, D2O): d
(ppm) 154.19, 74.30, 66.99, 43.69;
[
APeim]Cl: H NMR (400 MHz, D O): d (ppm) 7.43 (s,
2
1
4-(Phenoxymethyl)-1,3-dioxolan-2-one: H NMR (400
2
1
1
8
H), 4.20 (t, 2H), 4.11 (t, 2H), 2.69 (t, 2H), 2.01 (m, 2H),
.41 (t, 3H); FT-IR (KBr): 3426, 3145, 3090, 2948, 2868,
639, 1565, 1462, 1384, 1339, 1165, 1110, 1079, 1030,
MHZ, CDCl ) d (ppm) 7.31 (m, 2H), 7.02 (t, 1H), 6.91 (dd,
3
2H), 5.03 (mm, 1H), 4.62 (t, 1H), 4.54 (dd, 1H), 4.24 (dd,
13
-
1
42, 762, 647 cm
1
.
1H), 4.15 (dd, 1H); C NMR (100 MHz, D2O): d (ppm)
157.76, 154.60, 129.71, 122.03, 114.63, 74.07, 66.90, 66.26;
[
APbim]Cl: H NMR (400 MHz, D O): d (ppm) 7.41 (s,
2
1
4-Phenyl-1,3-dioxolan-2-one: H NMR (400 MHZ,
2
H), 4.17 (t, 2H), 4.08 (t, 2H), 2.55 (t, 2H), 1.92 (m, 2H), 1.75
(
m, 3H), 1.22 (m, 2H), 0.82 (m, 3H); FT-IR (KBr): 3420,
CDCl ) d (ppm) 7.46 (d, 3H), 7.38 (m, 2H), 5.69 (t, 1H), 4.82
3
1
3
3
1
142, 3091, 2959, 2874, 1645, 1562, 1462, 1382, 1330, 1165,
-
(t, 1H), 4.36 (dd, 1H); C NMR (100 MHz, D2O): d (ppm)
154.83, 135.84, 129.74, 129.25, 125.88, 78.00, 71.17;
1
110, 1059, 1030, 839, 753, 664, 644, 622 cm
1
.
1
Cis-hexahydrobenzo [1, 3] dioxol-2-one: H NMR (400
[
APbim]I: H NMR (400 MHz, D O): d (ppm) 7.45 (s,
2
2
1
3
1
H), 4.19 (t, 2H), 4.13 (t, 2H), 2.66 (t, 2H), 1.99 (m, 2H),
.78 (m, 3H), 1.25 (m, 2H), 0.84 (m, 3H); FT-IR (KBr):
445, 3137, 3084, 2957, 2872, 1637, 1564, 1461, 1385,
MHZ, CDCl ) d (ppm) 4.69 (m, 2H), 1.91 (m, 4H), 1.64
(m, 2H), 1.42 (m, 2H), C NMR (100 MHz, D2O): d (ppm)
155.39, 75.78, 26.63, 19.03.
3
1
3
-
1
332, 1163, 1110, 1077, 1024, 825, 752, 664, 636 cm
.
2
.2 Coupling Propylene Oxide and CO to Form
2
3 Results and Discussions
Propylene Carbonate
3.1 Catalytic Performance of Different Catalysts
The coupling reaction was carried out in a 50 ml stainless
steel autoclave equipped with a magnetic stirrer. For each
typical reaction process: imidazolium ionic liquid
Propylene carbonate synthesis from CO and propylene
2
oxide was carried out in the presence of a series of amino-
functional imidazolium ionic liquids under identical
(
0.71 mmol) and propylene oxide 1a (5.0 ml, 71.5 mmol)
123