Chemistry Reference
In-Depth Information
Scheme 12 Synthesis of teranthene derivative [
90
]
Fig. 27 X-Ray crystal structures of teranthene 119 and bond length of bisanthene and teranthene
[
90
]. Reprinted with permission from [
90
]. Copyright 2010 American Chemical Society
with the bisanthene. The bond length of C
8
-C
18
was 1.424
´
, being significantly
shorter than sp
2
C-C single bond (1.467
´
) and the corresponding one in
bisanthene (1.447
´
), which resulted from the enforcement of biradical resonance
contribution (120). Alternatively, from an energy point of view, the lost C-C
p
-bond energy of 270 kJ mol
1
can be fully compensated by three times the
aromatic stabilization energy of 90 kJ mol
1
, suggesting that both Kekul
´
and
biradical forms contribute equally to the ground state.
