Chemistry - A European Journal,
Journal Year:
2024,
Volume and Issue:
30(19)
Published: Jan. 25, 2024
Abstract
Helical
nanographenes
have
garnered
substantial
attention
owing
to
their
finely
adjustable
optical
and
semiconducting
properties.
The
strategic
integration
of
both
helicity
heteroatoms
into
the
nanographene
structure,
facilitated
by
a
boron‐oxygen‐based
multiple
resonance
(MR)
thermally
activated
delayed
fluorescence
(TADF),
elevates
its
photophysical
chiroptical
features.
This
signifies
introduction
an
elegant
category
helical
that
combines
(TADF)
(CPL)
In
this
direction,
we
report
synthesis,
optical,
properties
boron,
oxygen‐doped
Π‐extended
nanographene.
π‐extension
induces
distortion
in
DOBNA‐incorporated
nanographene,
endowing
pair
helicenes,
(
P)‐
B2NG
,
M)‐
exhibiting
circularly
polarized
luminescence
with
g
lum
−2.3×10
−3
+2.5×10
respectively.
exhibited
MR‐TADF
lifetime
below
5
μs,
reasonably
high
quantum
yield
(50
%).
Our
molecular
design
enriches
opens
up
new
opportunities
multidisciplinary
fields.
Angewandte Chemie International Edition,
Journal Year:
2024,
Volume and Issue:
63(35)
Published: June 21, 2024
The
mature
synthetic
methodologies
enable
us
to
rationally
design
and
produce
chiral
nanographenes
(NGs),
most
of
which
consist
multiple
helical
motifs.
However,
inherent
chirality
originating
from
twisted
geometry
has
just
emerged
be
employed
in
NGs.
Herein,
we
report
a
red-emissive
NG
constituted
orthogonally
arranged
two-fold
π-skeletons
at
contorted
pyrene
core
contributes
optical
transitions
S
Angewandte Chemie International Edition,
Journal Year:
2024,
Volume and Issue:
63(14)
Published: Jan. 27, 2024
Abstract
Reactions
of
open‐shell
molecular
graphene
fragments
are
typically
thought
as
undesired
decomposition
processes
because
they
lead
to
the
loss
desired
features
like
π‐magnetism.
Oxidative
dimerization
phenalenyl
peropyrene
shows,
however,
that
these
transformations
hold
promise
a
synthetic
tool
for
making
complex
structures
via
formation
multiple
bonds
and
rings
in
single
step.
Here,
we
explore
feasibility
using
this
“undesired”
reaction
build
up
strain
provide
access
non‐planar
polycyclic
aromatic
hydrocarbons.
To
end,
designed
synthesized
biradical
system
with
two
units
linked
biphenylene
backbone.
The
design
facilitates
an
intramolecular
cascade
helically
twisted
saddle‐shaped
product,
where
key
transformations—ring‐closure
ring‐fusion—occur
within
one
reaction.
negative
curvature
final
induced
by
formed
eight‐membered
ring,
was
confirmed
single‐crystal
X‐ray
diffraction
analysis
helical
twist
validated
resolution
product's
enantiomers
display
circularly
polarized
luminescence
high
configurational
stability.
Organic Letters,
Journal Year:
2024,
Volume and Issue:
26(25), P. 5227 - 5231
Published: March 27, 2024
Nucleophilic
substitution
of
9,10-dichlorooctafluoroanthracene
with
3,4-diethylpyrrole
and
subsequent
Scholl
reaction
give
the
annularly
fused
decapyrrollyl
anthracene.
Single
crystal
X-ray
analysis
revealed
a
highly
contorted
geometry
induced
by
combination
adjacent
heptagons,
forming
unique
7-7-6-7-7
topology.
The
end-to-end
twist
angle
along
acene
moiety
is
90°.
Cyclic
voltammetry
studies
reveal
6-electron
oxidation
waves.
Density
functional
theory
calculations
provided
further
insights
into
aromaticity
electronic
properties
this
twisted,
nitrogen-rich
nanographene.
structural
rigidity
high
racemization
energy
barrier
have
been
studied
theoretically
experimentally
VT-NMR.
Interdisciplinary materials,
Journal Year:
2024,
Volume and Issue:
3(4), P. 453 - 479
Published: May 11, 2024
Abstract
In
recent
years,
the
precisely
controlled
synthesis
of
chiral
twisted
molecular
carbons
has
emerged
as
a
forefront
topic
in
research
carbon
materials.
Molecular
refer
to
nanomaterials
synthesized
with
precision
at
atomic
level.
Through
rational
design,
rigid
and
stable
structures
can
be
synthesized.
The
exploration
field
is
key
fully
understanding
various
configurations
materials
delving
into
relationship
between
structure
design
functionality.
This
review
explores
such
nanographene,
nanobelts,
nanosheets,
graphdiyne,
etc.
It
emphasizes
role
photocyclization,
Scholl
reaction,
Diels–Alder
reactions
achieving
precise
control
discusses
range
innovative
strategies.
These
strategies
have
led
development
structures,
helical,
propeller,
Möbius
strip
configurations.
introduction
chirality,
combined
inherent
exceptional
optical
properties
nanocarbon
materials,
facilitated
creation
superior
chiroptical
performances.
advancement
driving
applications
fields
optoelectronics
optics.
Angewandte Chemie International Edition,
Journal Year:
2023,
Volume and Issue:
62(49)
Published: Oct. 17, 2023
The
bottom-up
synthesis
of
3D
tetrakis(hexa-peri-hexabenzocoronenyl)methane,
"tetrahedraphene",
is
reported.
This
molecular
nanographene
constituted
by
four
hexa-peri-hexabenzocoronene
(HBC)
units
attached
to
a
central
sp3
carbon
atom,
shows
highly
symmetric
arrangement
the
HBC
disposed
in
apex
tetrahedron.
X-ray
crystal
structure
reveals
tetrahedral
symmetry
molecule
and
packing
achieved
mostly
CH⋅⋅⋅π
interactions
since
interstitial
solvent
molecules
prevent
π⋅⋅⋅π
interactions.
In
solution,
tetrahedraphene
same
electrochemical
photophysical
properties
as
hexa-t
Bu-substituted
(t
Bu-HBC)
molecule.
However,
upon
water
addition,
it
undergoes
fluorescence
change
solution
precipitated
solid,
showing
an
aggregation
induced
emission
(AIE)
process,
probably
derived
from
restriction
rotation
and/or
vibration
HBCs.
Time-Dependent
Density
Functional
Theory
(TDDFT)
calculations
reveal
that
aggregation,
high
energy
region
band
decreases
intensity,
whereas
intensity
red
edge
signal
increases
presents
smoother
decay,
compared
non-aggregated
All
all,
excellent
correlation
between
our
simulations
experimental
findings
allows
explaining
colour
observed
different
solutions
increasing
fraction.
