Supramolecular Assembly of Edge Functionalized Top‐Down Chiral Graphene Quantum Dots
Angewandte Chemie International Edition,
Год журнала:
2022,
Номер
61(43)
Опубликована: Авг. 31, 2022
Abstract
The
construction
of
supramolecular
assemblies
heterogeneous
materials
at
the
nanoscale
is
an
open
challenge
in
science.
Herein,
new
chiral
graphene
quantum
dots
(GQDs)
prepared
by
amidation
reaction
introducing
amide
groups
and
pyrene
moieties
into
periphery
GQDs
are
described.
analytical
spectroscopic
data
show
efficient
chemical
functionalization
morphological
study
ensembles
using
SEM
AFM
microscopies
reveals
presence
highly
ordered
fibers
several
micrometers
length.
Fluorescence
studies,
emission
spectroscopy
confocal
microscopy,
reveal
that
stem
from
π‐π
stacking
both
pyrenes
GQDs,
together
with
hydrogen
bonding
interactions
groups.
Circular
dichroism
analysis
supports
nature
aggregates.
Язык: Английский
A Double Twisted Nanographene with a Contorted Pyrene Core
Angewandte Chemie International Edition,
Год журнала:
2024,
Номер
63(35)
Опубликована: Июнь 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
Язык: Английский
Helicity Modulation in NIR‐Absorbing Porphyrin‐Ryleneimides
Angewandte Chemie International Edition,
Год журнала:
2022,
Номер
61(18)
Опубликована: Фев. 7, 2022
Peripheral
substitution
of
a
π-extended
porphyrin
with
bulky
groups
produces
curved
chromophore
four
helical
stereogenic
units.
The
curvature
and
stereochemistry
such
porphyrins
can
be
controlled
by
varying
the
substituents,
coordinated
metal
ions,
apical
ligands.
In
particular,
when
achiral
saddle-shaped
free
bases
are
treated
large
i.e.,
Cd
Язык: Английский
A Double Twisted Nanographene with a Contorted Pyrene Core
Angewandte Chemie,
Год журнала:
2024,
Номер
136(35)
Опубликована: Июнь 21, 2024
Abstract
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
0
→S
1
vice
versa.
thus‐obtained
exhibited
robustness
on
its
redox
properties
through
2e
−
uptake/release.
chemical
oxidation
generated
stable
radical
cation
whose
absorption
covers
near‐infrared
I
II
regions.
Overall,
the
governs
electronic
nature
NG.
twist
operation
NGs
would
be,
therefore,
strategy
alter
conventional
induction
Язык: Английский
An Atropisomerism Study of Large Cycloarylenes: [n]Cyclo‐4,10‐Pyrenylenes’ Case
Chemistry - A European Journal,
Год журнала:
2023,
Номер
29(24)
Опубликована: Фев. 6, 2023
An
atropisomerism
of
large
cycloarylenes
was
studied
using
[n]cyclo-4,10-pyrenylenes
(n=6-21)
as
an
illustrative
example
with
two
simple
assumptions:
(1)
alternating
configurations
(R,S,R,S,…)
are
thermodynamically
most
stable,
and
(2)
three
consecutive
identical
(R,R,R
or
S,S,S)
prevented.
Ni-mediated
coupling
a
5,9-diiodopyrene
gave
series
directly-linked
cyclic
pyrene
oligomers
in
one-pot
reaction.
As-synthesized
hexamer
assigned
(R,S,S,R,R,S)
structure,
converted
into
(R,S,R,S,R,S)-form
upon
heating.
Cyclic
heptamer
consists
types
C2
symmetric
structures
predicted
from
assumption
(2),
one
which
convergent
to
another
by
Three
atropisomers
octamer
were
analyzed
the
possible
five
candidates
means
1
H
nuclear
magnetic
resonance
(NMR)
spectroscopy,
conversion
process
(R,S,R,S,R,S,R,S)
heating
investigated.
In
total,
according
rules,
analysis
could
be
performed
smoothly.
Язык: Английский
Helicity Modulation in NIR‐Absorbing Porphyrin‐Ryleneimides
Angewandte Chemie,
Год журнала:
2022,
Номер
134(18)
Опубликована: Фев. 7, 2022
Abstract
Peripheral
substitution
of
a
π‐extended
porphyrin
with
bulky
groups
produces
curved
chromophore
four
helical
stereogenic
units.
The
curvature
and
stereochemistry
such
porphyrins
can
be
controlled
by
varying
the
substituents,
coordinated
metal
ions,
apical
ligands.
In
particular,
when
achiral
saddle‐shaped
free
bases
are
treated
large
i.e.,
Cd
II
or
Hg
,
resulting
complexes
convert
to
chiral
propeller‐like
configurations.
X‐ray
diffraction
analyses
show
that
coordination
water
molecule
is
sufficient
induce
notable
bowl‐like
distortion
cadmium
complex,
which
however
retains
its
structure.
For
phenyl‐
tolyl‐substituted
derivatives,
conversion
thermodynamically
controlled,
whereas
bearing
4‐(
tert
‐butyl)phenyl
transform
into
their
forms
upon
heating.
latter
case,
was
converted
corresponding
base
other
without
any
loss
configurational
purity,
ultimately
providing
access
stable,
enantiopure
propellers.
Язык: Английский
Supramolecular Assembly of Edge Functionalized Top‐Down Chiral Graphene Quantum Dots
Angewandte Chemie,
Год журнала:
2022,
Номер
134(43)
Опубликована: Авг. 31, 2022
Abstract
The
construction
of
supramolecular
assemblies
heterogeneous
materials
at
the
nanoscale
is
an
open
challenge
in
science.
Herein,
new
chiral
graphene
quantum
dots
(GQDs)
prepared
by
amidation
reaction
introducing
amide
groups
and
pyrene
moieties
into
periphery
GQDs
are
described.
analytical
spectroscopic
data
show
efficient
chemical
functionalization
morphological
study
ensembles
using
SEM
AFM
microscopies
reveals
presence
highly
ordered
fibers
several
micrometers
length.
Fluorescence
studies,
emission
spectroscopy
confocal
microscopy,
reveal
that
stem
from
π‐π
stacking
both
pyrenes
GQDs,
together
with
hydrogen
bonding
interactions
groups.
Circular
dichroism
analysis
supports
nature
aggregates.
Язык: Английский