Table 1 Electronic properties of azaborines 1a and 1b
aromatic molecules and polymers. An interaction of the boron
empty orbital with the lone pair of the nitrogen suppresses the
Lewis acidity of the former, leading to increased stability of
these materials. This interaction is confirmed by X-ray crystallo-
graphy and DFT calculations. Planarity and rigidity of
azaborine-fused oligothiophenes as well as p-stacking
ordering in the solid state make them potential candidates
for semiconducting applications.
HOMO/eV
electrochem
(calc)
l
abs/nm
lem
nm
/
FPL
[%]
Eg/eV
opt (calc)
(log e)
1a
1b
395
407
410
34
25
ꢁ5.3
3.14
(4.58)
397
(4.74)
(ꢁ5.42)
–5.3
(–5.36)
(3.55)
3.12
(3.53)
We thank NSERC for supporting this work and CFI for the
infrastructure grant. OL is grateful to FQRNT for the PBEEE
fellowship. We thank Dr A. Moiseev and M. Morantz
(McGill) for the EPR and TGA measurements, respectively,
and F. Belanger (Universite de Montreal) for X-ray analysis.
´ ´ ´
Notes and references
z Prolonged (more than a few minutes) exposure to air leads to
oxidation of the fluoride addition product resulting in radical species.
It is, however, completely stable in the nitrogen atmosphere.
y A weaker red-shift upon Fꢁ addition was previously reported for
boryl-substituted dithienophospholes.9
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c
This journal is The Royal Society of Chemistry 2010
Chem. Commun., 2010, 46, 7007–7009 7009