Angewandte Chemie International Edition,
Год журнала:
2024,
Номер
63(30)
Опубликована: Май 10, 2024
Abstract
Although
helicenes
are
promising
molecules,
the
synthetic
difficulty
and
tediousness
have
often
been
problems,
only
small
amounts
of
optically
pure
obtained
by
using
chiral
HPLC
in
most
cases.
Herein,
aza[7]helicenes
or
closed‐aza[7]helicenes
with
(1
R
)‐menthyl
substituents
were
selectively
synthesized
via
intramolecular
Scholl
reaction,
diastereomeric
pairs
separated
silica
gel
column
chromatography.
The
further
transformed
into
corresponding
cyclic
dimers,
chiroptical
properties
investigated.
rigid
π‐frameworks
dimers
led
to
high
molar
extinction
coefficients
fluorescence
quantum
yields,
while
twisted
helicene
moieties
induced
clear
Cotton
effects
CPL
visible
region,
brightness
(
B
)
was
achieved.
Furthermore,
found
macrocyclic
cavity
two
NH
groups
suitable
for
selective
binding
a
fluoride
anion,
which
significantly
redshifted
red
region.
Angewandte Chemie International Edition,
Год журнала:
2023,
Номер
62(18)
Опубликована: Март 6, 2023
We
herein
present
the
synthetic
approach
to
a
new
antiaromatic
double
aza[7]helicene
C
that
features
NN-embedded
polycyclic
aromatic
hydrocarbons
(PAHs).
This
heteroatom-doped
helicene
showed
rarely
obtained
long-wavelength
emission
and
far-red
circularly
polarized
luminescence
(CPL)
in
solid
state.
These
optical
chiroptical
properties
could
be
ascribed
both
NN-PAH
core
structure
further
extension
through
angular
ring
fusions.
Such
unique
electronic
also
culminated
facile
chemical
oxidations
of
neutral
positively
charged
chiral
radical
(C⋅+
)
dication
species
(C2+
).
Interestingly,
DFT
computations
revealed
pyridazine
central
an
antiaromaticity-to-aromaticity
switching,
contrast
inversed
transition
for
helical
periphery
cationic
states.
The
reported
approaches
are
anticipated
lead
development
redox-active
systems
potential
applications
chiroptoelectronics,
spintronics
as
well
fluorescent
bioimaging.
Journal of the American Chemical Society,
Год журнала:
2023,
Номер
145(50), С. 27282 - 27294
Опубликована: Дек. 8, 2023
Remarkable
advances
have
been
achieved
in
solution
self-assembly
of
polypeptides
from
the
perspective
nanostructures,
mechanisms,
and
applications.
Despite
intrinsic
chirality
polypeptides,
promising
generation
aqueous
circularly
polarized
luminescence
(CPL)
based
on
their
has
rarely
reported
due
to
weak
fluorescence
most
indeterminate
mechanism.
Here,
we
propose
a
facile
strategy
for
achieving
CPL
simple
homopolypeptides
modified
with
terminal
group
featuring
both
twisted
intramolecular
charge
transfer
aggregation-induced
emission
properties.
A
morphology-dependent
can
be
observed
under
different
conditions
by
altering
solvents.
nanotoroid-dispersed
detectable
obtained
using
tetrahydrofuran
as
good
solvent
self-assembly,
which
is
attributed
involvement
chiral
environment
formed
homopolypeptide
chains.
However,
such
packing
mode
cannot
realized
nanorods
self-assembled
dioxane,
resulting
an
inactive
phenomenon.
Furthermore,
signals
greatly
amplified
co-assembly
achiral
small
molecule
derived
group.
This
work
not
only
provides
pathway
construct
CPL-active
nanomaterials
but
also
reveals
potential
mechanism
production,
transfer,
amplification
polypeptide-based
nanostructures.
Nature Synthesis,
Год журнала:
2024,
Номер
3(4), С. 545 - 553
Опубликована: Фев. 22, 2024
Abstract
The
introduction
and
precise
control
of
stereogenic
elements
in
chemical
structures
is
typically
a
challenging
task.
Most
asymmetric
methods
require
the
presence
heteroatom
starting
substrates
acting
as
an
anchor
point
for
successful
transfer
chiral
information.
For
this
reason,
compounds
comprising
only
carbon
atoms,
such
optically
active
molecular
nanographenes,
are
usually
obtained
racemates,
isolated
by
chromatographic
separation.
Here,
we
report
enantioselective
strategy
that
uses
three
stereocontrolled
synthetic
steps
to
introduce
extend
different
types
elements,
namely
central,
axial
helicoidal
chirality,
into
polycyclic
aromatic
structure.
Thus,
two
nanographene
layers
covalently
connected
through
triindane
core.
final
graphitization
Scholl
reaction
affords
formation
units
with
remarkable
enantiomeric
excesses,
high
stereochemical
stability
good
chiroptical
properties.
Journal of the American Chemical Society,
Год журнала:
2024,
Номер
146(25), С. 17428 - 17437
Опубликована: Июнь 12, 2024
Synthetic
challenges
toward
anomalous
structures
and
electronic
states
often
involve
handling
problems
such
as
insolubility
in
common
organic
solvents
oxidative
degradation
under
aerobic
conditions.
We
designed
benzo-annulated
aza[n]helicenes,
which
benefit
from
both
the
suppressed
elevation
of
highest
occupied
molecular
orbital
(HOMO)
energies
high
solubility
due
to
hydrogen
bonding
with
solvent
molecules
overcome
these
challenges.
This
strategy
enabled
synthesis
six
new
aza[n]helicenes
([n]AHs)
different
lengths
(n
=
9–19)
acyclic
precursors
via
one-pot
intramolecular
fusion
reactions.
The
all
synthesized
were
determined
by
X-ray
diffraction
(XRD)
analysis,
their
electrochemical
potentials
measured
cyclic
voltammetry.
Among
[17]AH
[19]AH
are
first
heterohelicenes
a
triple-layered
helix.
noncovalent
interaction
(NCI)
plots
confirm
existence
an
effective
π–π
between
layers.
absorption
fluorescence
spectra
red-shifted
helical
increased,
without
any
distinct
saturation
points.
optical
resolutions
N-butylated
[9]AH,
[11]AH,
[13]AH,
[15]AH
accomplished,
circular
dichroism
(CD)
circularly
polarized
luminescence
(CPL)
measured.
Thus,
structural,
(chir)optical,
properties
comprehensively
analyzed.
Advanced Optical Materials,
Год журнала:
2024,
Номер
12(18)
Опубликована: Май 20, 2024
Abstract
Molecular
chirality
plays
a
pivotal
role
across
the
disciplines
of
chemical
and
physical
sciences,
as
well
holding
significant
implications
in
realms
medicine
technology.
Chiral
macrocycles
have
attracted
recent
interests
synthetic
chemistry,
material
science,
supramolecular
chemistry.
Due
to
cyclic
arrangements
stereogenic
elements
or
special
orientations
confined
rigid
structures,
π‐conjugated
chiral
are
expected
be
highly
luminescent,
configurationally
stable,
thus
serve
develop
high‐performance
chiroptical
materials.
Given
rapid
progress
achieved
this
new
area
years,
it
is
highlight
concepts
breakthroughs.
This
minireview
will
offer
overview
wide
range
from
traditional
molecules
which
include
axially,
helically,
planar
skeletons
nanobelts
with
focus
on
structure‐function
relationship
between
unique
properties.
Advanced Optical Materials,
Год журнала:
2025,
Номер
unknown
Опубликована: Янв. 30, 2025
Abstract
Establishing
design
principles
to
engineer
molecules
that
exhibit
strong
circularly
polarized
luminescence
(CPL)‐brightness
across
the
UV,
visible
and
NIR
spectral
range
remains
an
unsolved
challenge.
To
achieve
a
large
CPL‐brightness,
main
difficulty
is
optimize
dissymmetry
factor
g
lum
.
Herein
described
discovery
multi‐helicene
system
based
on
series
of
annulated
[6]helicenes
perylenediimides,
exhibits
larger‐than‐linear
amplification
with
helicene
length.
Large
enhanced
fluorescent
quantum
yields
extinction
coefficients
are
also
observed
for
this
length
series.
Consequently,
oligomers
exceptional
CPL
brightness
(B
)
above
1
×
10
3
mol
−1
cm
Using
computational
methods
density
functional
theory
(DFT),
experimental
trend
shows
increase
glum
due
progressive
alignment
magnetic
(|m|)
electric
transition
(|µ|)
dipole
moment
vectors,
as
helical
backbone
grows
longer.
Chemical Science,
Год журнала:
2023,
Номер
15(2), С. 466 - 476
Опубликована: Окт. 25, 2023
The
presented
penta-
and
hexahelicenes
with
two
boron–nitrogen
groups
resemble
their
all-carbon
analogs
structurally
but
show
considerably
improved
(chir)optical
properties
like
absorptivities,
quantum
yields
luminescence
dissymmetries.
Journal of the American Chemical Society,
Год журнала:
2024,
Номер
146(32), С. 22600 - 22611
Опубликована: Авг. 5, 2024
Atomically
precise
synthesis
of
three-dimensional
boron-nitrogen
(BN)-based
helical
structures
constitutes
an
undeveloped
field
with
challenges
in
synthetic
chemistry.
Herein,
we
synthesized
and
comprehensively
characterized
a
new
class
molecular
carbons,
named
benzo-extended
[n]heli(aminoborane)s
(
Advanced Optical Materials,
Год журнала:
2024,
Номер
12(19)
Опубликована: Апрель 30, 2024
Abstract
Functional
materials
that
exhibit
circularly
polarized
luminescence
(CPL)
have
shown
immense
potential
in
applications
such
as
3D
optical
displays
and
advanced
information
encryption.
However,
facile
efficient
regulation
of
the
multiple
emission
properties
chiral
systems
has
remained
a
challenge
due
to
scarcity
suitable
complexity
systems.
Herein,
CPL
platform
is
fabricated
by
helical
co‐assembly
an
aldehyde‐functionalized
fluorane
dye
(Rhodol‐CHO,
6′‐(diethylamino)‐3′‐hydroxy‐3‐oxo‐3H‐spiro[isobenzofuran‐1,9′‐xanthene]‐4′‐carbaldehyde)
liquid
crystals,
which
can
efficiently
combine
stimuli‐responsive
characteristics
high
activity.
By
introducing
acid,
base,
compounds
containing
primary
amino
(─NH
2
)
groups,
property
system
be
easily
modified.
The
obtained
apparent
asymmetry,
with
g
lum
values
reaching
0.54–0.75).
Further,
these
modules
are
successfully
applied
multi‐mode
encryption,
highlighting
their
practical
utility.
Therefore,
this
study
presents
novel
strategy
for
developing
diverse
behaviors
based
on
simple‐designed
platform,
advancing
further
materials.