Organic Letters,
Journal Year:
2023,
Volume and Issue:
25(47), P. 8484 - 8488
Published: Nov. 20, 2023
We
investigated
the
chemical
and
physical
properties
of
internally
functionalized
dibenzo[g,p]chrysene
(DBC)
derivatives.
These
molecules
exhibit
chiral
double-helicene-like
structures
that
are
configurationally
stable
at
ambient
temperatures.
The
internal
substituents
control
conformational
change
in
excited
state,
thereby
modulating
emission
intensity.
Notably,
DBC
derivative
with
a
methylenedioxy
unit
undergoes
aromatization
through
elimination
substituent
upon
photoexcitation,
resulting
formation
DBC.
Angewandte Chemie International Edition,
Journal Year:
2023,
Volume and Issue:
63(4)
Published: Dec. 5, 2023
Abstract
The
development
of
chiral
compounds
with
enhanced
chiroptical
properties
is
an
important
challenge
to
improve
device
applications.
To
that
end,
optimization
the
electric
and
magnetic
dipole
transition
moments
molecule
necessary.
Nevertheless,
relationship
between
chemical
structure
such
quantum
mechanical
not
always
clear.
That
case
moment
(
m
)
for
which
no
general
trends
its
have
been
suggested.
In
this
work
we
propose
a
rationalization
improving
magnitude
in
different
families
compounds.
Performing
clustering
analysis
hundreds
transitions,
able
identify
single
group
|
value
maximized
along
helix
axis.
More
interestingly,
found
accurate
linear
(up
R
2
=0.994)
maximum
parameter
area
inner
cavity
helix,
thus
resembling
classical
behavior
solenoids.
This
research
provides
tool
rationalized
synthesis
improved
responses.
Journal of the American Chemical Society,
Journal Year:
2024,
Volume and Issue:
146(15), P. 10321 - 10330
Published: April 3, 2024
Polycyclic
hydrocarbons
with
diradical
and
polyradical
characters
usually
display
unique
reactivities
in
ring-cyclization
reactions.
However,
such
reactions
are
rarely
used
to
construct
π-extended
polycyclic
aromatic
hydrocarbons.
Here,
we
describe
the
synthesis
of
an
S-shaped
doubly
helical
singlet
diradicaloid
compound
its
facile
transformation
into
unprecedented
circumchrysene
via
a
two-stage
ring
cyclization,
which
includes:
(1)
eletrocylization
from
precursor
(2)
Scholl
reaction.
The
reaction
mechanism
was
investigated
through
Chemical Science,
Journal Year:
2024,
Volume and Issue:
15(37), P. 15170 - 15177
Published: Jan. 1, 2024
A
pair
of
CP-MR-TADF
enantiomers
with
high-order
B,N-embedded
hetero[8]helicene,
(
P
/
M
)-BN-TP-ICz,
was
constructed.
CP-OLEDs
exhibit
narrow
green
emission
peaking
at
540
nm
maximum
EQEs
32.0%
and
g
EL
s
approximately
7.70
×
10
−4
.
Asian Journal of Organic Chemistry,
Journal Year:
2023,
Volume and Issue:
12(12)
Published: Nov. 21, 2023
Abstract
Atomic
precise
chiral
molecules
with
all‐hydrocarbon
backbones,
such
as
helicenes
and
related
π‐extended
derivatives,
attract
critical
interests
due
to
their
great
application
potential
in
many
fields
(e.
g.,
optical
materials,
asymmetric
catalysis,
molecular
machines).
Herein,
the
main
development
of
these
past
decade
was
summarizes,
including
enantioselective
synthesis
helicenes,
helicene
extension
along
perpendicular
helical
axis,
well
following
both
directions,
namely
helix
axis
direction.
Angewandte Chemie International Edition,
Journal Year:
2024,
Volume and Issue:
63(45)
Published: Aug. 8, 2024
Doping
of
polycyclic
conjugated
hydrocarbons
(PCHs)
with
sulfur
atoms
is
becoming
more
and
important
as
a
means
creating
unique
functional
materials.
Recently,
thiophene-containing
multiple
helicenes
have
garnered
enormous
attention
due
to
their
intriguing
electronic
(chir)optical
properties
compared
carbohelicenes.
However,
the
efficient
synthesis
thiopyran-containing
underlying
doping
mechanisms
are
rather
unexplored.
Herein,
structural
analysis
double
[7]helicene
3
reported.
X-ray
crystallographic
reveals
its
dication
C
Precision Chemistry,
Journal Year:
2024,
Volume and Issue:
2(9), P. 488 - 494
Published: Aug. 13, 2024
Multiple
helicenes
display
distinct
aromatic
cores
characterized
by
highly
twisted
rings
that
are
shared
or
fused
with
constituent
helicene
moieties.
Diversifying
these
unlocks
avenues
for
creating
multiple
properties
and
topologies.
Herein
we
report
the
synthesis
of
a
quadruple[6]helicene
featuring
pyrene
as
core.
The
involved
key
steps
annulative
π-extension
reaction
Scholl
reaction.
By
extending
along
axial
direction,
degree
contortion
core
can
be
controlled
from
nearly
flat
to
twisted.
Notably,
exhibits
significant
red-shift
0.49
eV
compared
quadruple[4]helicenes,
which
arises
both
augmented
effective
conjugation
due
enhanced
twisting.
Quantum
chemical
calculations
demonstrate
in
adeptly
governs
energy
levels
HOMO
LUMO,
offers
an
alternative
strategy
beyond
mere
enlargement
π
backbone.
An
intriguing
serendipitous
finding
reveals
formation
one-molecule-thick
supramolecular
homochiral
nanosheets
through
self-interlocking
interactions
enantiomers
single
crystals,
rare
packing
motif
helicenes.
Chirality,
Journal Year:
2024,
Volume and Issue:
36(5)
Published: May 1, 2024
Abstract
The
adjustment
of
the
main
helical
scaffold
in
helicenes
is
a
fundamental
strategy
for
modulating
their
optical
features,
thereby
enhancing
potential
diverse
applications.
This
work
explores
influence
elongation
(n
=
5–9)
on
structural,
photophysical,
and
chiroptical
features
symmetric
oxa[
n
]helicenes.
Crystal
structure
analyses
revealed
structural
variations
with
extension,
impacting
torsion
angles,
pitch,
packing
arrangements.
Through
theoretical
investigations
using
density
functional
theory
(DFT)
calculations,
impact
extension
aromaticity,
planarity
distortion,
heightened
chiral
stability
were
discussed.
Photophysical
studied
through
spectrophotometric
analysis,
insights
gained
time‐dependent
DFT
(TD‐DFT)
calculations.
Following
resolution
via
high‐performance
liquid
chromatography
(HPLC),
properties
both
enantiomers
oxa[7]helicene
oxa[9]helicene
investigated.
A
slight
variation
]helicenes
from
[7]
to
[9]
induced
an
approximately
three‐fold
increase
dissymmetry
factors
biggest
values
of|
g
lum
|
(2.2
×
10
−3
)
compared
to|
|of
(0.8
),
findings
discussed
supported
by
TD‐DFT
Angewandte Chemie,
Journal Year:
2024,
Volume and Issue:
136(35)
Published: June 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
