Biomedical Engineering Reference
In-Depth Information
N
N
N
Br
N
Br
-
Br
-
O
O
O
OR
N
OR
OR
RO
RO
N
RO
hv
(i)
(ii)
RO
RO
RO
OR
OR
OR
OR
OR
OR
36
37
38
M
w
= 5352, M
n
= 1192
g 224 Col
r
244 I
Figure 9.14
Synthesis of triphenylene-imidazole-based polymer: (i) toluene, rel ux, 8 h;
(ii) 2,2-dimethoxy-2-phenylacetophenone, 100 C, r.t., h
v
.
Two symmetrical gemini dimers based on triphenylene and ammonia
have been reported by Gupta
et al.
[81]. h ese dimers
35
were prepared
by reacting ω-brominated triphenylene with tetramethylene-1,2-diamine
in toluene. h ese compounds exhibited enantiotropic behavior with Col
h
mesophase. Although degree of order present is less in these systems.
9.3.1.2.4 Ionic Discotic Polymer Based on Triphenylene
Hybridization of ionic liquids and triphenylene discotics may lead to novel
discotic materials with interesting properties. With this aim in mind, Pal
et
al.
[82] prepared triphenylene-imidazolium-based ionic polymer
38
accord-
ing to Figure 9.14. h e ω-bromosubstituted triphenylene
36
was reacted with
1-vinylimidazole to provide imidazole salt of triphenylene
37
which showed
Col
r
mesophase at 72 C on cooling, and no crystallization was observed
up to room temperature. h e photopolymerization was performed using
2,2-dimethoxy-2-phenylacetophenone as photoinitiator. h e polymer
38
obtained was a glassy material at room temperature which went to Col
r
phase
at 224 C on heating and became isotropic at 244 C. On cooling, mesophase
appeared around 209 C and remained stable down to room temperature.
9.3.1.3 Perylene
Perylene-based ionic complex [83] has been generated by ionic self-assembly
process between ammonium-based dicationic perylenediimide and anionic
ethylhexylsulfosuccinate (Figure 9.15). h is compound
39
exhibited both
