Advanced Functional Materials,
Год журнала:
2025,
Номер
unknown
Опубликована: Май 13, 2025
Abstract
Two
dimeric
tetracene
complexes,
Pt(L
tc
)
2
Cl
and
Pd(L
,
have
been
synthesized
by
coordination
of
a
pyridyl
substituted
acene‐
to
Pt(II)
Pd(II)
metal
center.
The
photophysical
properties
the
two
dimers
are
characterized
compared
with
free
ligand
L
as
well
corresponding
monomeric
complexes
(
)(
ref
)Cl
)(L
shed
light
on
processes
intramolecular
up‐
down‐conversion,
namely
triplet‐triplet
annihilation
singlet
fission,
respectively.
Both
show
high
fluorescence
quantum
yields,
while
emission
is
heavily
reduced
in
complexes.
Dimer
exhibits
efficient
fission
within
1.6
ns
form
correlated
triplet
pair
(T
1
T
),
confirming
that
coupling
mediated
through
over
remarkably
long
inter‐chromophore
distances.
Subsequently,
dissociates
into
triplets
+
yields
ca.
50%.
Moreover,
due
isoenergetic
level
excited
state
for
dimers,
some
observed
undergo
up‐conversion
return
state,
followed
upconverted
fluorescence.
On
other
hand,
photoexcitation
gives
kinetic
behavior
similar
monomer
no
but
fast
intersystem
crossing
hundreds
picoseconds.
It
noted
formation
dimer
low,
non‐radiative
decay
excitons
ground
dominates
both
cases.
all
metal–organic
subtle
intrachromophore
charge‐transfer
characteristics
polar
solvents
schemes
apolar
solvents.
Inorganic Chemistry,
Год журнала:
2025,
Номер
unknown
Опубликована: Фев. 26, 2025
Square-planar
d8-configured
metal
complexes
and
their
excited
states
play
a
key
role
in
photocatalysis,
sensing,
optoelectronic
devices.
However,
metal-to-ligand
charge-transfer
(MLCT)
involving
transition
metals,
particularly
those
with
3d8
electronic
configuration,
present
challenges
due
to
rapid
nonradiative
relaxation
via
low-lying
metal-centered
(MC)
states.
In
this
work,
an
isoelectronic
isostructural
series
of
cyclometalated
[MX(dpb)]
M
=
Ni(II),
Pd(II),
Pt(II),
dpb
1,3-di(2-pyridyl)phenide,
auxiliary
ligand
X
chlorido,
azido,
triazolato
were
studied
by
UV/vis
absorption,
steady-state,
time-resolved
photoluminescence
spectroscopy
solution
frozen
glassy
matrix
at
77
K,
along
DFT
calculations.
Consistently,
the
Pd(II)
Pt(II)
exhibited
characteristic
emission
from
triplet
ligand-centered
(3LC)
contrast,
Ni(II)
triazolatoCOOCH3,COOCH3
ligands
nonemissive
low
room
temperatures,
presence
MC-type
ligand-field
On
other
hand,
[Ni(triazolatoCoumarin,COOCH3)(dpb)]
showed
phosphorescence
T5
state
since
restrictive
environment
limits
structural
relaxation,
while
temperature,
primary
is
singlet
LC
coumarin
moiety
free
ligand.
Nature Communications,
Год журнала:
2025,
Номер
16(1)
Опубликована: Фев. 25, 2025
Cryptochiral
compounds
are
indispensable
in
biology
systems
and
medical
applications,
yet
the
development
of
high-performance
detection
method
remains
challenging.
Here,
we
report
a
hinge-like
dinuclear
Pt(II)
complex
as
stereodynamic
probe
for
cryptochirality
sensing.
This
features
constrained,
closed
conformation
achieved
through
synergistic
intramolecular
π
−
stacking
metal-metal
interactions
between
cyclometalated
wings.
The
shows
robust
chiroptical
response
to
center-to-axial
chiral
induction
during
rapid
condensation
with
cryptochiral
that
adopts
more
energetically
favorable
conformation.
resulting
intense
Cotton
effects
at
long
wavelengths
enable
in-situ
circular
dichroism
analysis
determinate
absolute
configuration
enantiometric
composition
molecules.
Furthermore,
near-infrared
phosphorescence
characteristics
hinge
have
been
explored
develop
it
an
optical
sensor
accurate
quantification
With
its
dual
CD
capabilities,
this
great
potential
high-throughput
screening
analysis.
authors
complexes
probes
Angewandte Chemie International Edition,
Год журнала:
2024,
Номер
63(33)
Опубликована: Май 7, 2024
Abstract
Near‐Infrared
(NIR)
phosphorescence
at
room
temperature
is
challenging
to
achieve
for
organic
molecules
due
negligible
spin–orbit
coupling
and
a
low
energy
gap
leading
fast
non‐radiative
transitions.
Here,
we
show
supramolecular
host–guest
strategy
harvest
the
from
low‐lying
triplet
state
of
C
64
nanographene
tetraimide
1
.
H
NMR
X‐ray
analysis
confirmed
:
2
stoichiometric
binding
Pt(II)
porphyrin
on
two
π‐surfaces
While
free
does
not
emission
in
NIR,
complex
solution
shows
NIR
77
K.
Further,
between
860–1100
nm,
(
λ
max
=900
τ
avg
=142
μs)
was
observed
solid‐state
sample
drop‐casted
preformed
solution.
Theoretical
calculations
reveal
non‐zero
isoenergetic
S
T
3
π‐stacked
[
⋅
porphyrin]
complex.
External
heavy‐atom‐induced
along
with
rigidification
protection
oxygen
promotes
both
intersystem
crossing
first
excited
singlet
into
manifold
lowest
Journal of the American Chemical Society,
Год журнала:
2024,
Номер
146(28), С. 19042 - 19049
Опубликована: Июль 1, 2024
A
bimetallic,
two-coordinated
carbene-metal-amine
(cMa)
Au(I)
complex
featuring
a
twisted
tandem
carbene
structure
(NHC1-Au-NHC2-Au-carbazolyl)
was
synthesized.
The
molecular
in
single
crystals
revealed
large
dihedral
angle
between
the
two
ligands,
while
bridged
NHC2
and
carbazolyl
(Cz)
ligands
were
coplanar.
bluish
green
thermally
stimulated
delayed
phosphorescence
(TSDP)
observed
with
an
emission
lifetime
over
70
μs,
which
can
be
attributed
to
spin
allowed
diabatic
population
of
high-lying
emissive
triplet
state
from
3LE
characterized
low-lying
ones.
small
rotation
energy
barrier
Cz
along
coordination
bond
conformers
angles
Cz.
ICT
S1
consequently
stabilized
achieve
accessible
gap
facilitate
ISC
triplets
S1,
leading
activated
fluorescence
(TADF).
Simultaneous
TSDP
TADF
dual
recorded
its
doped
polymer
film
owing
coexistence
these
different
conformers.
Chemistry - A European Journal,
Год журнала:
2023,
Номер
29(32)
Опубликована: Март 14, 2023
Organic
spintronics
has
caused
a
huge
revolution
in
creating
highly
efficient
low-power
circuits.
Spin
manipulation
organic
cocrystals
become
promising
strategy
to
uncover
more
chemicophysical
properties
for
diverse
applications.
In
this
Minireview,
we
summarize
the
recent
advancements
of
spin
charge-transfer
cocrystals,
and
briefly
describe
possible
mechanisms
behind
them.
Beside
known
(spin
multiplicity,
mechanoresponsive
spin,
chiral
orbit
spin-crossover)
binary/ternary
other
phenomena
radical
transport
are
also
summarized
discussed.
Hopefully,
deep
understanding
current
achievements,
challenges
perspectives
will
offer
clear
direction
introduction
cocrystals.
Abstract
Two
series
with
three
Pt(II)
complexes
each
(
PtL
Ph
‐n
,
Fpy
)
bearing
asymmetric
tetradentate
ligands
as
dianionic
luminophores
variable
alkyl
chain
lengths
were
synthesized.
Hence,
ligand
is
distinguished
by
one
of
its
cyclometallating
rings
(phenyl
vs.
2,6‐difluoropyrid‐3‐yl).
Steady‐state
and
time‐resolved
photoluminescence
spectroscopic
studies
in
diluted
solutions
at
room
temperature
glassy
matrices
77
K
show
that
the
emissive
state
mainly
centered
on
invariantly
electron‐rich
cyclometalated
side
while
second
ring
regulates
admixture
ligand‐centered
metal‐to‐ligand
charge‐transfer
character.
radiative
rates
can
be
controlled,
indicated
quantum‐mechanical
calculations,
which
also
explain
temperature‐dependent
trend
phosphorescence
rate
constants.
Studies
condensed
phases
(single‐crystal
X‐ray
diffractometry,
polarized
optical
microscopy,
differential
scanning
calorimetry,
steady‐state
micro(spectro)scopy)
showed
development
a
smectic
A
mesophase
for
fluorinated
species
two
longest
chains.
Nuclear
magnetic
resonance‐based
thermodynamics
aggregation
solution
confirm
marked
enthalpic
stabilization
aggregates
mediated
polar
2,6‐difluoropyrid‐3‐yl
moiety
(and
to
lesser
extent
dispersive
forces
between
chains).
On
other
hand,
negative
entropy
dominated
restriction
degrees
freedom
involving
peripheral
moieties
upon
stacking,
becomes
increasingly
relevant
longer
All
these
factors
control
Pt···Pt
coupling,
crucial
interaction
design
photofunctional
mesogens
based
complexes.
Inorganic Chemistry,
Год журнала:
2024,
Номер
63(12), С. 5315 - 5319
Опубликована: Март 12, 2024
Metal-mediated
self-assembly
of
isocyanides
and
methyl
4-aminopyrimidine-5-carboxylate
leads
to
luminescent
PdII
PtII
complexes
featuring
C,N-cyclometalated
acyclic
diaminocarbene
(ADC)
ligands.
The
solid-state
properties
these
derivatives
are
attributed
their
triplet-state
metal/metal-to-ligand
charge-transfer
(3MMLCT)
nature,
which
is
driven
by
attractive
intermolecular
M···M
interactions
further
reinforced
the
intramolecular
π–π
even
in
structure
Pd
compound,
first
Pd-ADC
phosphor
reported.
