Chemistry Reference
In-Depth Information
Fig. 23 Examples of rylenes as functional materials [
75
-
78
]
with significantly reduced surface roughness and void space, leading to electron
mobility up to 0.088 cm
2
V
1
s
1
. This method opens up a new route toward the
solution based fabrication of the crystalline thin films of sparingly soluble higher
rylene bisimides.
High order rylenes represent extension of conjugation along the longer molecu-
lar axis, while lateral extension of conjugation of perylene bisimides leads to
another intriguing 2D aromatic network. A series of triply linked oligo-perylene
bisimides 91-95 were reported in Wang's group (Fig.
24
), and the conjugation can
be expanded up to four perylene bisimides fused together at the bay region [
79
-
81
].
These systems were synthesized by copper-involved condensation of tetrabromo
(chloro)-perylene bisimides along the bay region under different conditions. Due to
the two possible coupling positions, there are structural isomers for higher
analogues. These fully conjugated graphene-type compounds display broad and
red-shifted absorption and strong electron-accepting ability.
3.2 Anthenes and Periacenes
The same fusion mode with anthracene instead of naphthalene leads to another type
of extended 2D aromatic network termed “anthene”. When two anthracene units are
fused together by three single bonds between neighboring anthryls, it is called
bisanthene (96), and longer homologues are named teranthene (97) and
