Synlett,
Год журнала:
2023,
Номер
35(13), С. 1480 - 1487
Опубликована: Сен. 4, 2023
Abstract
The
combination
of
different
distortion
motifs
in
nanographenes
and
polycyclic
conjugated
hydrocarbons
has
been
the
focus
significant
attention
during
last
decade.
continual
discovery
multiple
carbon
allotropes
fueled
field.
A
plethora
research
groups
around
globe
are
engaged
developing
methods
for
preparation
discrete
graphene
or
fullerene
fragments
new
allotropes.
goal
is
to
fully
understand
structure–property
relationships
these
systems.
Herein,
we
present
our
journey
contributions
field,
from
development
a
synthetic
methodology
towards
functionalized
heptagon-containing
hexa-peri-hexabenzocoronenes
through
saddle-helix
hybrid
nanographenes,
study
cumulenic
open-shell
systems,
embedded
with
higher
order
carbocycles,
their
electronic
properties
on-surface
by
single-molecule
conductance.
1
Introduction
2
Finding
Cornerstone
Scaffold
3
Saddle-Helix
Hybrid
Nanographenes
4
Cumulenic
Diradicaloid
Systems
5
Supramolecular
Studies
6
Octagon-
Nonagon-Embedded
7
Molecular
Electronics
On-Surface
8
Outlook
Chemical Reviews,
Год журнала:
2023,
Номер
123(24), С. 13952 - 13965
Опубликована: Ноя. 10, 2023
Sterically
hindered
C═C
double
bonds
often
deform
into
a
bent
or
twisted
geometry.
Thus,
many
overcrowded
ethylenes
anthraquinodimethanes
can
adopt
multiple
conformations,
such
as
folded
form
form,
which
are
interconvertible
under
the
application
of
external
stimuli.
A
perpendicular
with
biradical
character
also
be
adopted
when
designed
to
incorporate
stable
carbon-based
radical
unit,
is
involved
in
stimuli-responsive
magnetic
switching
accompanied
by
structural
change.
This
review
focuses
on
recent
advances
development
strained
π-electron
systems
and
reveals
factors
that
affect
mutual
interconversion
behavior.
The
energy
barrier
for
conformational
isomers
affected
tricyclic
skeleton
bulky
substituents
bonds,
whereas
relative
stability
increases
additional
insertion
9,10-anthrylene
units
bonds.
Angewandte Chemie International Edition,
Год журнала:
2024,
Номер
63(47)
Опубликована: Авг. 19, 2024
Abstract
Thiele's
Hydrocarbons
(THs)
featuring
a
9,10‐anthrylene
core
with
switchable
geometric
and
electronic
configurations
offer
exciting
possibilities
in
advanced
functional
materials.
Despite
significant
advances
main
group‐based
diradicaloids
contemporary
chemistry,
group
THs
containing
an
anthrylene
cores
have
remained
elusive,
primarily
due
to
the
lack
of
straightforward
synthetic
strategies
inherent
high
reactivity
these
species.
In
this
study,
we
utilize
anthracene‐based
phosphine
synthon
demonstrate,
for
first
time,
facile
high‐yielding
strategy
robust
P‐functionalized
overcrowded
ethylenes
(OCEs)
within
TH
family.
These
OCEs
feature
non‐symmetric
environment,
incorporating
(thio)
xanthyl
phosphaalkene
termini.
We
systematically
probe
structures
derivatives
illustrate
impact
isolobal
motif
on
quinoidal/diradicaloid
character.
Notably,
compounds
exhibit
dynamic
redox
behavior,
leading
orthogonally
twisted
conformational
changes
upon
oxidation,
kinetically
locked
redox‐couple.
Abstract
The
open‐shell
organic
and
carbon‐based
systems,
with
either
a
doublet,
triplet
or
higher
spin‐states,
play
key
role
in
contemporary
research,
opening
potential
applicability
for
several
crucial
fields.
Among
those
derivatives,
specific
attention
has
been
given
to
p
‐phenylene‐based
systems
derived
from
the
original
Thiele
hydrocarbon.
These
stabilize
an
diradicaloid
resonance
structure
thermally
accessible
state
are
quinone‐benzene
(Clar's
sextet)
equilibrium.
In
our
discussion,
we
very
carefully
choose
examples
which
focus
on
fundamental
derivatives
that
merge
diatropic
subunits,
ready
two
unpaired
electrons
via
dynamic
modulation
of
geometry.
This
process
provides
additional
factor
energy
aromatics,
mostly
responsible
stabilization
electrons.
Chemistry - An Asian Journal,
Год журнала:
2025,
Номер
unknown
Опубликована: Апрель 28, 2025
Abstract
Toward
the
synthesis
and
evaluation
of
stable
radical‐based
2D
frameworks,
a
diacetylene‐bridged
tri(9‐anthryl)methyl
(
TAntM
)
radical
dimer
was
designed
synthesized.
X‐ray
crystallographic
analysis
revealed
strong
spin–spin
interaction
between
units
through
diacetylene
linker,
resulting
in
closed‐shell
[5]cumulene
structure
as
form.
Variable‐temperature
(VT)
1
H‐NMR
measurements
at
high
temperatures
showed
signal
broadening
for
aromatic
protons,
indicating
an
increased
population
thermally
excited
triplet
species
metastable
To
facilitate
spin‐state
modulation
by
external
stimuli,
mechanical
grinding
solid
state
conducted.
Due
to
its
reactivity,
partially
induced
structural
changes
state.
Angewandte Chemie International Edition,
Год журнала:
2023,
Номер
62(45)
Опубликована: Авг. 30, 2023
A
modular
approach
for
the
synthesis
of
isolable
crystalline
Schlenk
hydrocarbon
diradicals
from
m-phenylene
bridged
electron-rich
bis-triazaalkenes
as
synthons
is
reported.
EPR
spectroscopy
confirms
their
diradical
nature
and
triplet
electronic
structure
by
revealing
a
half-field
signal.
computational
analysis
state
to
be
ground
state.
As
proof-of-principle
methodology,
4,6-dimethyl-m-phenylene
was
further
utilized
coupling
unit
between
two
alkene
motifs.
The
steric
conjunction
4,6-dimethyl
groups
substantially
twists
substituents
at
nonbonding
electron
bearing
centers
relative
central
motif.
result,
spin
delocalization
decreased
exchange
unpaired
spins,
hence,
significantly
reduced.
Notably,
108
years
after
Schlenk's
m-phenylene-bis(diphenylmethyl)
diradical,
first
time
we
were
able
isolate
its
derivative
with
same
spacer,
i.e.
m-phenylene,
radical
in
form.
Chemistry - A European Journal,
Год журнала:
2024,
Номер
30(47)
Опубликована: Май 23, 2024
Cyclophane-type
dications
with
two
units
of
xanthylium
were
designed,
the
expectation
that
intramolecular
interaction
between
cation
could
induce
changes
in
absorption
and
redox
behavior.
The
desired
synthesized
via
macrocyclic
diketone
as
a
key
intermediate,
which
was
efficiently
obtained
by
stepwise
etherification.
X-ray
UV/Vis
measurements
revealed
cyclophane-type
adopt
stacking
structure
both
crystal
solution.
Due
to
caused
π-π
units,
considerable
blue
shift
compared
corresponding
monocations
two-stage
one-electron
reduction
process
observed
dications.
Furthermore,
upon
electrochemical
dications,
formation
biradicals
radical
species
demonstrated
spectroscopy
several
isosbestic
points
at
stages.
Therefore,
cation-stacking
approach
is
promising
way
provide
novel
properties
due
perturbation
their
molecular
orbitals
stabilize
reduced
even
though
they
have
open-shell
characters.
Angewandte Chemie,
Год журнала:
2023,
Номер
135(45)
Опубликована: Авг. 30, 2023
Abstract
Beschrieben
wird
ein
modularer
Ansatz
für
die
Synthese
von
kristallinen,
diradikalischen
Schlenk‐Kohlenwasserstoffen
ausgehend
m‐
Phenylen‐verbrückten,
elektronenreichen
bis‐Triazaalkenen.
Das
Auftreten
eines
Halbfeldsignals
im
EPR‐Spektrum
bestätigt
diradikalische
Natur
sowie
den
Triplett‐Zustand
der
Spezies.
Dass
auch
dem
Grundzustand
entspricht,
durch
eine
computergestützte
Analyse
untermauert.
Um
Modularität
des
Ansatzes
zu
belegen,
wurde
zudem
4,6‐Dimethyl‐
m
‐Phenylen‐Brücke
als
Verbindung
zwischen
beiden
Alken‐Motiven
untersucht.
Der
sterische
Anspruch
4,6‐Dimethyl‐Gruppen
führt
einer
substantiellen
Rotation
Substituenten
an
radikalischen
Zentren
relativ
zum
koppelnden
‐Phenylen‐Motiv.
Daraus
ergibt
sich
Verringerung
Spin‐Delokalisierung,
was
in
signifikant
reduzierten
Austauschkopplung
ungepaarten
Spinzuständen
resultiert.
Bemerkenswerterweise,
konnten
wir
erstmalig
und
dies
108
Jahre
nach
‐Phenylen‐Bis(Diphenylmethyl)‐Diradikals
Schlenk
Derivat
mit
gleichen
zwei
kristalliner
Form
isolieren.
Angewandte Chemie,
Год журнала:
2024,
Номер
136(47)
Опубликована: Авг. 19, 2024
Abstract
Thiele's
Hydrocarbons
(THs)
featuring
a
9,10‐anthrylene
core
with
switchable
geometric
and
electronic
configurations
offer
exciting
possibilities
in
advanced
functional
materials.
Despite
significant
advances
main
group‐based
diradicaloids
contemporary
chemistry,
group
THs
containing
an
anthrylene
cores
have
remained
elusive,
primarily
due
to
the
lack
of
straightforward
synthetic
strategies
inherent
high
reactivity
these
species.
In
this
study,
we
utilize
anthracene‐based
phosphine
synthon
demonstrate,
for
first
time,
facile
high‐yielding
strategy
robust
P‐functionalized
overcrowded
ethylenes
(OCEs)
within
TH
family.
These
OCEs
feature
non‐symmetric
environment,
incorporating
(thio)
xanthyl
phosphaalkene
termini.
We
systematically
probe
structures
derivatives
illustrate
impact
isolobal
motif
on
quinoidal/diradicaloid
character.
Notably,
compounds
exhibit
dynamic
redox
behavior,
leading
orthogonally
twisted
conformational
changes
upon
oxidation,
kinetically
locked
redox‐couple.
Angewandte Chemie,
Год журнала:
2024,
Номер
unknown
Опубликована: Ноя. 15, 2024
Abstract
The
development
of
new
π‐conjugated
motifs
opens
pathways
to
previously
unexplored
classes
organic
semiconductors
and
functional
dyes.
In
this
study,
five‐
seven‐membered
carbocycles
were
fused
at
the
ortho
bay
regions
electron‐deficient
perylenes,
starting
from
a
common
dialdehyde
precursor.
Structural
analysis
resulting
perylene
tetraesters,
dianhydrides,
diimides
(PDIs)
revealed
three
distinct
ring‐fusion
patterns
defined
stereochemistry.
PDI
cycloheptatrienes
demonstrated
susceptibility
acid‐catalyzed
transarylation,
involving
tropylium
cation
intermediates,
which
can
be
used
preparatively.
Under
superacidic
conditions,
cations
directly
observed
shown
undergo
hydride‐transfer
reductions.
Additionally,
bis(heptafulvene)
was
synthesized
by
dehydrogenating
suitably
substituted
cycloheptatriene.
final
system
contains
two
quinomethane
units,
protonated
yield
stable
tropylium‐like
dication.
Angewandte Chemie International Edition,
Год журнала:
2024,
Номер
unknown
Опубликована: Ноя. 15, 2024
Abstract
The
development
of
new
π‐conjugated
motifs
opens
pathways
to
previously
unexplored
classes
organic
semiconductors
and
functional
dyes.
In
this
study,
five‐
seven‐membered
carbocycles
were
fused
at
the
ortho
bay
regions
electron‐deficient
perylenes,
starting
from
a
common
dialdehyde
precursor.
Structural
analysis
resulting
perylene
tetraesters,
dianhydrides,
diimides
(PDIs)
revealed
three
distinct
ring‐fusion
patterns
defined
stereochemistry.
PDI
cycloheptatrienes
demonstrated
susceptibility
acid‐catalyzed
transarylation,
involving
tropylium
cation
intermediates,
which
can
be
used
preparatively.
Under
superacidic
conditions,
cations
directly
observed
shown
undergo
hydride‐transfer
reductions.
Additionally,
bis(heptafulvene)
was
synthesized
by
dehydrogenating
suitably
substituted
cycloheptatriene.
final
system
contains
two
quinomethane
units,
protonated
yield
stable
tropylium‐like
dication.