Journal of the American Chemical Society,
Journal Year:
2023,
Volume and Issue:
145(51), P. 28137 - 28145
Published: Dec. 14, 2023
The
incorporation
of
nonbenzenoid
rings
into
the
hexagonal
networks
graphenoid
nanostructures
is
immense
importance
for
electronic,
magnetic,
and
mechanical
properties,
but
underlying
mechanisms
ring
fusion
are
rather
unexplored.
Here,
we
report
synthesis
characterization
a
rippled
C84
molecular
carbon,
which
contains
10
(five-,
seven-,
eight-membered
rings)
that
contiguously
fused
to
give
cyclic
geometry.
impart
high
solubility,
configurational
stability,
multiple
reversible
redox
behaviors,
unique
aromaticity,
narrow
band
gap
system.
Moreover,
this
carbon
nanostructure
allows
further
functionalization
via
electrophilic
substitution
metalation
reactions,
enabling
access
finely
tuned
derivatives.
Interestingly,
both
bowl-shaped
planar
conformations
core
in
observed
solid
state.
Additionally,
displays
ambipolar
transport
characteristics.
Accounts of Chemical Research,
Journal Year:
2023,
Volume and Issue:
56(3), P. 363 - 373
Published: Jan. 26, 2023
ConspectusUnderstanding
and
harnessing
the
properties
of
nanoscale
molecular
entities
are
considered
as
new
frontiers
in
basic
chemistry.
In
this
regard,
synthetic
nanographene
with
atomic
precision
has
attracted
much
attention
recently.
For
instance,
taking
advantage
marvelous
bonding
capability
carbon,
flat,
curved,
ribbon-type,
or
cone-shaped
nanographenes
have
been
prepared
highly
controllable
elegant
manner,
allowing
one
to
explore
fascinating
architectures
intriguing
optical,
electrochemical,
magnetic
characteristics.
This
stands
stark
contrast
other
carbon-rich
nanomaterials,
such
graphite
oxides
carbon
quantum
dots,
which
preclude
thorough
investigations
because
complicate
structural
defects.
Undoubtedly,
contributes
strongly
modern
aromatic
chemistry
represents
a
vibrant
field
that
may
deliver
transforming
functional
materials
crucial
for
optoelectronics,
nanotechnologies,
biomedicine.Nonetheless,
many
cases,
synthesis
characterization
compounds
demanding.
Low
solubility,
high
strain,
undesired
selectivity,
well
incomplete
excessive
C-C
bond
formation
common
impediments,
require
formidable
efforts
control
geometry,
modulate
edge
structure,
achieve
accurate
doping,
push
upper
size
boundary.
These
endeavors
indispensable
establishing
structure-property
relationships,
lay
down
foundation
exploring
at
level
sophistications.In
Account,
we
summarize
our
contributions
by
presenting
series
helical
nanographenes,
hexapole
[7]helicene
(H7H),
nitrogen-doped
H7H,
[9]helicene
(H9H),
superhelicene,
supertwistacene.
kind
giant
reaches
domain
albeit
precise
structure.
It
provides
unique
platform
study
chirality
nanoscale.
We
discuss
methods
point
out,
particular,
strengths
pitfalls
Scholl
oxidation,
expected
be
valuable
making
general.
addition,
illustrate
their
exciting
electrochemical
photophysical
performance,
include,
but
not
limited
to,
reversible
multielectron
redox
chemistry,
record
panchromatic
absorption,
impressive
photothermal
behavior,
extremely
strong
Cotton
effect.
unusual
characteristics
convincingly
traced
back
three-dimensional
conjugated
architectures,
highlighting
critical
roles
π-electron
delocalization,
heteroatom-doping,
substitution,
symmetry
determining
nanographenes'
functions.
Lastly,
put
forward
understanding
on
challenges
opportunities
lies
ahead
hope
Account
will
inspire
ever
more
ambitious
achievements
from
attractive
area
research.
Angewandte Chemie International Edition,
Journal Year:
2023,
Volume and Issue:
62(15)
Published: Feb. 16, 2023
A
novel
chiral
nanographene
(i.e.
EP9H)
with
a
pentadecabenzo[9]helicene
core
fragment
has
been
synthesized
and
fully
characterized.
Single-crystal
X-ray
diffraction
unambiguously
confirms
the
helical
structure.
The
fluorescence
emission
of
EP9H
is
located
in
near
infrared
region
(λem
=684
nm)
medium
quantum
yield
(0.10)
for
helicene
derivatives.
Cyclic
voltammetry
reveals
its
seven
quasi-reversible
redox
states
from
-2
to
+5.
Furthermore,
enantiopure
displays
distinct
CD
signals
broad
spectral
range
300
700
nm.
Notably,
compared
reported
small
organic
molecules,
an
outstanding
|glum
|
value
4.50×10-2
BCPL
as
304
M-1
cm-1
.
Angewandte Chemie International Edition,
Journal Year:
2024,
Volume and Issue:
63(11)
Published: Jan. 17, 2024
Abstract
We
report
a
unique
category
of
π‐extended
diaza[7]helicenes
with
double
negative
curvatures.
This
is
achieved
by
two‐fold
regioselective
heptagonal
cyclization
the
oligoarylene‐carbazole
precursors
through
either
intramolecular
C−H
arylation
or
Scholl
reaction.
The
fusion
two
rings
in
helical
skeleton
dramatically
increases
strain
and
forces
terminal
carbazole
moieties
to
stack
compressed
fashion.
presence
deformable
negatively
curved
endows
resulting
dynamic
chiral
skeletons,
aggregation‐induced
emission
feature
relatively
low
racemization
barrier
ca.
25.6
kcal
mol
−1
.
Further
π‐extension
on
subsequently
leads
more
sophisticated
C
2
‐symmetric
homochiral
triple
helicene.
Notably,
these
show
structure‐dependent
stacking
upon
crystallization,
switching
from
heterochiral
packing
intra‐layer
stacking.
Interestingly,
helicene
molecules
spontaneously
resolve
into
lamellar
structure
3
1
helix
symmetry.
Upon
ultrasonication
nonsolvent,
crystals
can
be
readily
exfoliated
large‐area
ultrathin
nanosheets
height
4.4
nm
corresponding
layers
stacked
thicker
constituted
even‐numbered
molecular
lamellae.
Moreover,
regular
hexagonal
thin
platelets
size
larger
than
30
μm
fabricated
flash
aggregation.
ACS Nano,
Journal Year:
2025,
Volume and Issue:
unknown
Published: Feb. 18, 2025
Porous
aromatic
frameworks
(PAFs)
are
a
fundamental
group
of
porous
materials
characterized
by
their
distinct
structural
features
and
large
surface
areas.
These
synthesized
from
building
units
linked
strong
carbon–carbon
bonds,
which
confer
exceptional
rigidity
long-term
stability.
PAFs
functionalities
may
arise
directly
the
intrinsic
chemistry
or
through
postmodification
motifs
using
well-defined
chemical
processes.
Compared
to
other
traditional
such
as
zeolites
metallic-organic
frameworks,
demonstrate
superior
stability
under
severe
treatments
due
robust
bonding.
Even
in
challenging
environments,
ease
functionalization
flexibility
specificity.
Research
on
has
significantly
expanded
accelerated
over
past
decade,
necessitating
comprehensive
overview
key
advancements
this
field.
This
review
provides
an
in-depth
analysis
recent
advances
synthesis,
functionalization,
dimensionality
PAFs,
along
with
distinctive
properties
wide-ranging
applications.
explores
innovative
methodologies
strategies
for
functionalizing
structures,
manipulation
tailor
specific
potential
Similarly,
application
areas,
including
batteries,
absorption,
sensors,
CO2
capture,
photo-/electrocatalytic
usages,
supercapacitors,
separation,
biomedical
discussed
detail,
highlighting
versatility
addressing
modern
scientific
industrial
challenges.
Angewandte Chemie International Edition,
Journal Year:
2022,
Volume and Issue:
62(4)
Published: Nov. 26, 2022
Chiral
nanographenes
with
both
high
fluorescence
quantum
yields
(ΦF
)
and
large
dissymmetry
factors
(glum
are
essential
to
the
development
of
circularly
polarized
luminescence
(CPL)
materials.
However,
most
studies
have
been
focused
on
improvement
glum
,
whereas
how
design
highly
emissive
chiral
is
still
unclear.
In
this
work,
we
propose
a
new
strategy
achieve
ΦF
by
helical
π-extension
strongly
luminescent
chromophores
while
maintaining
frontier
molecular
orbital
(FMO)
distribution
pattern.
nanographene
perylene
as
core
two
dibenzo[6]helicene
fragments
wings
has
synthesized,
which
exhibits
record
93
%
among
reported
excellent
CPL
brightness
(BCPL
32
M-1
cm-1
.
Organic Chemistry Frontiers,
Journal Year:
2023,
Volume and Issue:
10(16), P. 4167 - 4197
Published: Jan. 1, 2023
This
review
will
highlight
several
recent
and
lesser-reviewed
works
related
to
the
preparation
of
chiral
nanographenes,
specifically
focusing
on
structures
prepared
by
non-Scholl
methods.
Angewandte Chemie International Edition,
Journal Year:
2023,
Volume and Issue:
62(29)
Published: May 18, 2023
The
incorporation
of
heteroatoms
and/or
heptagons
as
the
defects
into
helicenes
expands
variety
chiroptical
materials
with
novel
properties.
However,
it
is
still
challenging
to
construct
boron-doped
heptagon-containing
high
photoluminescence
quantum
yields
(PLQYs)
and
narrow
full-width-at-half-maximum
(FWHM)
values.
We
report
an
efficient
scalable
synthesis
a
quadruple
helicene
4Cz-NBN
two
nitrogen-boron-nitrogen
(NBN)
units
double
4Cz-NBN-P1
bearing
NBN-doped
heptagons,
latter
could
be
formed
via
two-fold
Scholl
reaction
former.
exhibit
excellent
PLQYs
up
99
%
65
FWHM
24
nm
22
nm,
respectively.
emission
wavelengths
are
tunable
stepwise
titration
experiments
toward
fluoride,
enabling
distinguished
circularly
polarized
luminescence
(CPL)
from
green,
orange
(4Cz-NBN-P1-F1)
yellow
(trans/cis-4Cz-NBN-P1-F2)
near-unity
broader
circular
dichroism
(CD)
ranges.
five
structures
aforementioned
four
were
confirmed
by
single
crystal
X-ray
diffraction
analysis.
This
work
provides
design
strategy
for
construction
non-benzenoid
multiple
exhibiting
emissions
superior
PLQYs.