Chemistry Reference
In-Depth Information
Antiaromaticity in Nonbenzenoid Oligoarenes
and Ladder Polymers
Rebecca R. Parkhurst and Timothy M. Swager
Abstract Polycyclic aromatic hydrocarbons (PAHs) and fully-conjugated ladder
polymers are leading candidates for organics electronics, as their inherent confor-
mational rigidity encourages electron delocalization. Many of these systems consist
of fused benzenoid or heterocyclic aromatic rings. Less frequently, however, PAHs
are reported with character that alternates between the aromaticity of benzene
fragments and the antiaromaticity of a nonbenzenoid moiety. This chapter will
focus on recent work published on the theory, synthesis, and properties of two such
systems: [N]phenylenes containing 4
p
-electron cyclobutadienoid character, and
diaryl[
a,e
]pentalenes containing 8
p
-electron pentalenoid character.
Keywords [N]Phenylenes
Antiaromaticity
Diaryl[
a,e
]pentalenes
Ladder
polymers
Nontraditional graphitic materials
Contents
1
Introduction .................................................................................. 142
2
[N]Phenylenes and Related Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142
2.1 Recent Synthetic Developments in [N]Phenylenes .................................. 144
2.2 Photophysical Properties of [N]Phenylenes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148
2.3 Reactivity of [N]Phenylenes and Related Materials . . . . . . . . ......................... 151
2.4 Applications of Phenylene-Containing Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153
2.5 Polymeric and Graphitic [N]Phenylenes . . . . . . . . . .................................... 159
