Biomedical Engineering Reference
In-Depth Information
R
2
R
3
R
1
R
1
R
2
X
-
R
1
Br
N
R
1
R
2
R
3
O
R
2
14R
3
THF
B
O
N
N
Br
N
R
3
Pd(PPh
3
)
4
K
2
CO
3
THF/H
2
O
Br
X
-
16
X
-
N
Br
13
15
17a-e
R
3
R
1
R
2
R
3
R
2
N
X
-
R
1
N
R
1
R
1
R
1
R
2
N
N
THF/CH
3
CN
n-BuLi
THF
R
2
N
R
2
Br
N
N
Br
R
3
N
Br
R
3
X
-
R
3
X
-
N
16
N
Br
14
18
19a-c
R
3
R
1
R
2
R
3
R
2
R
1
R
1
R
2
R
3
X
-
O
O
R
1
N
R
1
R
2
R
3
THF/CH
3
CN
R
2
R
3
13
Br
N
N
Br
Pd(PPh
3
)
4
K
2
CO
3
THF/H
2
O
N
Br
X
-
X
-
N
16
Br
20
21
22a-c
R
3
R
1
R
2
Figure 9.10
Synthesis routes to Benzene-based ionic liquid crystals.
71] have reported tripodal ionic liquid crystals based on pyridine (
17a-e
),
pyrimidine (
19a-c
) and quinoline (
22a-c
) salts with benzene core at the
center. h ese salts were prepared by quarterization reactions of the cor-
responding phenylpyridine, phenylpyrimidine or phenylquinoline deriva-
tives with 1,3,5-tribromomethylbenzene followed by counterion exchange,
as shown in Figure 9.10. As we go from pyridine to quinoline salts, meso-
phase also changed from columnar rectangular to columnar hexago-
nal mesophase (Table 9.2). Also, as the size of the counterion decreased
from PF
6
to Br, additional cubic mesophases were observed, and when
