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.
Organometallics,
Год журнала:
2024,
Номер
43(16), С. 1736 - 1751
Опубликована: Май 2, 2024
The
synthesis,
characterization,
and
photophysical
properties
of
16
d8-configured
metal
complexes
featuring
Pt(II)
or
Pd(II)
centers
with
N*N∧C-coordinated
ligands
is
presented.
Key
findings
include
the
discovery
that
distortion
coordination
plane
improves
solubility,
as
observed
for
compounds
a
pyridine-N-donor
instead
thiazole
unit.
In
addition,
we
found
substitution
chlorido
coligand
by
monodentate
cyanido
unit
enhances
emitters'
performance
decreasing
nonradiative
decay
rate.
switch
from
to
resulted
in
weaker
ligand
field
splitting
reduced
spin–orbit
coupling,
leading
longer
average
lifetimes
without
luminescence
at
room
temperature.
Interestingly,
cyclometalated
thiophenyl
moiety
exhibited
red-shifted
dual
emission.
Finally,
photoinduced
generation
singlet
dioxygen
(1O2),
highly
reactive
oxygen
species,
critically
influenced
chelated
coligands,
they
control
1O2
photoproduction
quantum
yields.
These
results
have
significant
implications
photocatalysis,
optoelectronics,
biomedical
applications.
The Chemical Record,
Год журнала:
2024,
Номер
24(6)
Опубликована: Июнь 1, 2024
In
the
last
past
twenty
years,
research
on
luminescent
platinum
(II)
complexes
has
been
intensively
developed
for
useful
application
such
as
organic
light
emitting
diodes
(OLEDs).
More
recently,
new
photoluminescent
based
diazine
ligands
(pyrimidine,
pyrazine,
pyridazine,
quinazoline
and
quinoxaline)
have
in
this
context.
This
review
will
summarize
photophysical
properties
of
most
phosphorescent
Pt(II)
described
literature
compare
results
to
pyridine
analogues
whenever
possible.
Based
emission
color,
photoluminescence
quantum
yield
(PLQY)
values,
relationship
between
structure
modification,
are
highlighted.
Tuning
yields
solution
solid
state
and,
some
complexes,
aggregation
induced
(AIE)
or
thermally
activated
delayed
fluorescence
(TADF)
described.
When
OLEDs
built
from
external
efficiency
(EQE)
values
luminance
different
wavelengths
cases,
chromaticity
coordinates
obtained
devices,
given.
Finally,
highlights
growing
interest
studies
OLED
applications.
ABSTRACT
The
idea
of
preparation
a
water‐soluble
Pt‐containing
AIEgen
was
successfully
realized
by
direct
reversible
addition‐fragmentation
transfer
copolymerization
Pt(II)
complex
(
LPtPV
)
containing
vinyl
group
and
polyvinylpyrrolidone
p(VP)
).
resulting
block‐copolymer
p(VP‐
b
‐LPtPV)
5–8
chromophores
exhibits
intriguing
photophysical
properties—strong
solvent
concentration
dependence
absorption
emission
characteristics.
Various
physicochemical
analytical
methods
(NMR
spectroscopy,
XRD
analysis,
ESI‐MS,
AUC,
DLS,
ICP‐OES,
GPC,
viscometry,
TEM)
were
used
to
characterize
the
initial
complex,
its
binuclear
analogs,
.
obtained
data
indicate
that
properties
latter
are
dictated
type
aggregation
process
rather
than
solvatochromic
effects.
It
is
shown
at
low
in
organic
solvents,
platinum
either
absent
(dimethylformamide)
or
occurs
predominantly
intramolecular
level
(MeCN),
whereas
aqueous
media,
readily
aggregates
into
micellar‐type
nanoparticles
with
hydrophilic
corona
hydrophobic
core,
which
strong
intra‐
intermolecular
Pt···Pt
and/or
π···π
interactions
result
significant
red
shift
down
600
816
nm,
respectively.
Despite
NIR
area
where
commonly
quenched
nonradiative
vibrational
relaxation,
an
increase
quantum
yield
complete
agreement
typical
aggregation‐induced
(AIE)
emitters’
behavior.
Quantum
mechanics/molecular
mechanics
simulations
processes
also
confirm
trends
relationship
between
mode
behavior,
particularly,
variations
energy
gaps
ground
state
AIEgens
their
excited
singlet
triplet
states.
Transition
metal
complexes
are
well-known
for
their
efficient
light
emission
and
promising
applications
ranging
from
bioimaging
to
light-emitting
diodes.
In
solution,
interactions
between
the
centers
of
two
become
possible
drastically
change
photophysical
properties.
For
real-world
devices,
solid-state
materials
consisting
these
molecules
preferable.
Recently,
ligand-controlled
aggregation
platinum(II)
palladium(II)
into
molecular
single
crystals
controlled
formation
metal-metal
contacts
have
been
demonstrated.
Here,
we
show
how
distance
can
be
tuned
in
a
way
by
exerting
pressure
on
crystal.
Using
optical
spectroscopy
inside
diamond
anvil
cell,
find
strong
reversible
piezochromism
up
18
GPa.
time-dependent
density
functional
theory,
attribute
wavelength
shift
reduction
enhanced
π
orbital
overlap
dimers.
Inorganic Chemistry,
Год журнала:
2025,
Номер
unknown
Опубликована: Март 27, 2025
While
Pt(II)
complexes
containing
doubly
cyclometalated
ligands
as
tridentate
luminophores
are
well
studied,
the
synthetic
accessibility
of
their
Pd(II)
counterparts
was
lacking
for
a
long
time.
Inspired
by
recent
report
on
synthesis
[Pd(dpp)(PPh3)]
involving
C∧N∧C
coordination
mode
(with
dpp2–
=
2,6-di(phenid-2-yl)pyridine)
and
following
our
own
work
closely
related
Pt(II)-based
compounds,
we
produced
series
[Pd(dpp)(PnPh3)]
(Pn
P,
As,
Sb)
optimizing
procedure
exploring
reactivity
in
process.
Our
study
electrochemical
(cyclic
voltammetry)
photophysical
(UV–vis
absorption
emission,
transient
(TA)
spectroscopy)
properties
Pd(C∧N∧C)
represents
first
characterization.
We
observed
UV–vis
bands
down
to
450
nm
HOMO–LUMO
gaps
around
3.2
V,
which
show
minimal
variation
with
different
PnPh3
coligands.
A
more
pronounced
influence
coligand
time-resolved
emission
TA
spectroscopy.
The
highest
photoluminescence
quantum
yield
(ΦL)
found
[Pd(dpp)(AsPh3)],
reaching
0.06.
interpretation
spectroscopic
data
is
supported
(TD-)DFT
calculations.
Additionally,
structural
several
dinuclear
complexes,
including
precursor
{[Pd(dppH)(μ-Cl)]}2
multiple
decomposition
products
sensitive
compounds
[Pd(dpp)(PnPh3)].
Applied Organometallic Chemistry,
Год журнала:
2025,
Номер
39(5)
Опубликована: Апрель 8, 2025
ABSTRACT
Two
novel
binuclear
cyclometalated
Pd
(II)
complexes
with
two
tridentate
phenylpyridine
ligands
and
a
N^N
ligand
were
readily
synthesized.
Both
structures
unambiguously
characterized
via
X‐ray
single
crystal
diffraction,
nuclear
magnetic
resonance
(NMR)
spectra,
high‐resolution
mass
spectrometry
(HRMS).
The
structure
data
reveals
that
the
Pd–Pd
distances
of
[Pd(1,3‐di(2‐pyridyl)benzene)]
2
(Dpf)
(DpfH
=
N
,
′‐diphenyl
formamidine)
Pd1
[Pd(1,3‐di(2‐pyridyl)benzene]
(
α
‐Car)
‐CarH
‐carboline)
Pd2
measure
3.0046(3)
3.1518(8)
Å,
respectively.
absorption
spectra
display
metal–metal‐to‐ligand
charge
transfer
(MMLCT)
transitions.
In
solid
state,
they
show
triplet
emissions
at
635
607
nm,
While
in
1
wt%
PMMA
film,
emission
peaks
are
located
602
571
contrast,
both
very
weak
solution
their
maximum
wavelengths
significantly
red‐shifted.
Based
on
photophysical
properties,
films
quartz
squares
was
placed
different
organic
or
acid
solvents
for
30
min
then
utilized
to
detect
solvent
vapor.
film
showed
unique
quenching
vapor
acetone.
