Chemistry Reference
In-Depth Information
O
O
HO
HO
H
2
N
NH
2
OH
OH
2.
+
H
2
N
NH
2
O
O
O
O
N
N
N
n
N
Different ladder polyquinoxalines were prepared as well. One example is shown below [
233
]:
O
O
+
H
2
N
H
2
N
NH
2
NH
2
O
O
N
N
N
N
n
Some ladder polyquinoxalines were found to be stable in air at 460
C and in nitrogen up to 683
C.
Not all attempts at formations of ladder polymers yielded completely cyclized fused ring
structures. For instance, an attempt to form a polymer from tetraaminonaphthalene with naphthalene
tetracarboxylic acid dianhydride failed to yield complete cyclizations [
222
].
An interesting polymer containing macrocyclic rings was formed from pyromellitic tetranitrile by
condensation with dianilino ether [
223
]:
NC
NC
CN
CN
+
H
2
N
O
NH
2
