Angewandte Chemie,
Journal Year:
2023,
Volume and Issue:
135(25)
Published: March 8, 2023
Abstract
Ultraviolet
(UV,
λ
<400
nm)
light
is
essential
for
various
photochemical
reactions,
but
its
intensity
in
the
solar
spectrum
very
low,
and
sources
that
artificially
generate
high‐energy
UV
are
inefficient
environmentally
unfriendly.
A
solution
to
this
problem
photon
upconversion
(UC)
from
visible
(vis,
>400
light.
Among
several
mechanisms,
UC
based
on
triplet‐triplet
annihilation
(TTA‐UC)
particular
has
made
remarkable
progress
recent
years.
The
development
of
new
chromophores
enabled
highly
efficient
conversion
low‐intensity
into
In
review,
we
summarize
visible‐to‐UV
TTA‐UC,
their
production
films
application
processes
such
as
catalysis,
bond
activation
polymerization.
Finally,
challenges
opportunities
future
material
applications
will
be
discussed.
Journal of the American Chemical Society,
Journal Year:
2023,
Volume and Issue:
145(9), P. 4903 - 4920
Published: Feb. 21, 2023
Many
coordination
complexes
and
organometallic
compounds
with
the
4d6
5d6
valence
electron
configurations
have
outstanding
photophysical
photochemical
properties,
which
stem
from
metal-to-ligand
charge
transfer
(MLCT)
excited
states.
This
substance
class
makes
extensive
use
of
most
precious
least
abundant
metal
elements,
consequently
there
has
been
a
long-standing
interest
in
first-row
transition
photoactive
MLCT
Semiprecious
copper(I)
its
completely
filled
3d
subshell
is
relatively
straightforward
well
explored
case,
but
3d6
partially
d-orbitals
lead
to
energetically
low-lying
metal-centered
(MC)
states
that
can
cause
undesirably
fast
state
deactivation.
Herein,
we
discuss
recent
advances
made
isoelectronic
Cr0,
MnI,
FeII,
CoIII
compounds,
for
long-lived
become
accessible
over
past
five
years.
Furthermore,
possible
future
developments
search
new
subshells
next-generation
applications
photophysics
photochemistry.
ACS Nano,
Journal Year:
2023,
Volume and Issue:
17(4), P. 3259 - 3288
Published: Feb. 17, 2023
Using
light
to
control
matter
has
captured
the
imagination
of
scientists
for
generations,
as
there
is
an
abundance
photons
at
our
disposal.
Yet
delivering
beyond
surface
many
photoresponsive
systems
proven
challenging,
particularly
scale,
due
attenuation
via
absorption
and
scattering
losses.
Triplet–triplet
annihilation
upconversion
(TTA-UC),
a
process
which
allows
low
energy
be
converted
high
photons,
poised
overcome
these
challenges
by
allowing
precise
spatial
generation
its
nonlinear
nature.
With
wide
range
sensitizer
annihilator
motifs
available
TTA-UC,
researchers
seek
integrate
materials
in
solution
or
solid-state
applications.
In
this
Review,
we
discuss
nanoengineering
deployment
strategies
highlight
their
uses
recent
state-of-the-art
examples
TTA-UC
integrated
both
Considering
implementation
tactics
application-specific
requirements,
identify
critical
needs
push
TTA-UC-based
applications
from
academic
curiosity
scalable
technology.
Angewandte Chemie International Edition,
Journal Year:
2023,
Volume and Issue:
62(25)
Published: March 8, 2023
Ultraviolet
(UV,
λ<400
nm)
light
is
essential
for
various
photochemical
reactions,
but
its
intensity
in
the
solar
spectrum
very
low,
and
sources
that
artificially
generate
high-energy
UV
are
inefficient
environmentally
unfriendly.
A
solution
to
this
problem
photon
upconversion
(UC)
from
visible
(vis,
λ>400
light.
Among
several
mechanisms,
UC
based
on
triplet-triplet
annihilation
(TTA-UC)
particular
has
made
remarkable
progress
recent
years.
The
development
of
new
chromophores
enabled
highly
efficient
conversion
low-intensity
into
In
review,
we
summarize
visible-to-UV
TTA-UC,
their
production
films
application
processes
such
as
catalysis,
bond
activation
polymerization.
Finally,
challenges
opportunities
future
material
applications
will
be
discussed.
Angewandte Chemie International Edition,
Journal Year:
2023,
Volume and Issue:
62(16)
Published: Jan. 23, 2023
Charge
transfer
(CT)
in
molecular
electron
donor-acceptor
systems
is
pivotal
for
artificial
photosynthesis,
photocatalysis,
photovoltaics
and
fundamental
photochemistry.
We
summarized
the
recent
development
study
of
CT
discussed
its
application
thermally
activated
delayed
fluorescence
(TADF)
emitters.
The
direct
experimental
proof
spin
multiplicity
charge
separated
(CS)
state
with
pulsed
laser
excited
time-resolved
paramagnetic
resonance
(TREPR)
spectroscopy
was
discussed.
Experimental
determination
exchange
energy
(J)
CS
state,
magnetic
field
effect
on
yield
or
lifetime
introduced.
accompanying
CT,
studied
EPR
spectra
briefly
Tuning
kinetics
selective
vibration
excitation
linker
(the
bridge)
IR
pulse
presented.
Above
all,
these
studies
show
that
there
are
more
fun
than
simply
monitoring
formation
cations
anions
yields
this
area.
Angewandte Chemie International Edition,
Journal Year:
2022,
Volume and Issue:
62(8)
Published: Nov. 18, 2022
Several
energy-demanding
photoreactions
require
harsh
UV
light
from
inefficient
sources.
The
conversion
of
low-energy
visible
to
high-energy
singlet
states
via
triplet-triplet
annihilation
upconversion
(TTA-UC)
could
offer
a
solution
for
driving
such
reactions
under
mild
conditions.
We
present
the
first
annihilator
with
an
emission
maximum
in
UVB
region
that,
combined
organic
sensitizer,
is
suitable
blue-to-UVB
upconversion.
was
successfully
employed
as
energy
donor
subsequent
FRET
activations
aliphatic
carbonyls.
This
hitherto
unreported
UC-FRET
reaction
sequence
directly
monitored
using
laser
spectroscopy
and
applied
mechanistic
irradiation
experiments
demonstrating
feasibility
Norrish
chemistry.
Our
results
provide
clear
evidence
novel
blue
light-driven
substrate
or
solvent
activation
strategy,
which
important
context
developing
more
sustainable
light-to-chemical
systems.
Angewandte Chemie International Edition,
Journal Year:
2023,
Volume and Issue:
62(46)
Published: Sept. 21, 2023
Square-planar
NiII
complexes
are
interesting
as
cheaper
and
more
sustainable
alternatives
to
PtII
luminophores
widely
used
in
lighting
photocatalysis.
We
investigated
the
excited-state
behavior
of
two
complexes,
which
isostructural
with
luminescent
complexes.
The
initially
excited
singlet
metal-to-ligand
charge
transfer
(1
MLCT)
states
decay
metal-centered
(3
MC)
within
less
than
1
picosecond,
followed
by
non-radiative
relaxation
3
MC
electronic
ground
state
9-21
ps.
This
contrasts
population
an
emissive
triplet
ligand-centered
LC)
upon
excitation
analogues.
Structural
distortions
responsible
for
this
discrepant
lead
dark
far
lower
energy
LC
compounds.
Our
findings
suggest
that
if
these
structural
could
be
restricted
rigid
coordination
environments
stronger
ligand
fields,
four-coordinate
decelerated
such
or
MLCT
become
accessible.
These
insights
relevant
make
fit
photophysical
photochemical
applications
relied
on
until
now.
Advanced Science,
Journal Year:
2024,
Volume and Issue:
unknown
Published: July 10, 2024
Materials
exhibiting
thermally
activated
delayed
fluorescence
(TADF)
based
on
transition
metal
complexes
are
currently
gathering
significant
attention
due
to
their
technological
potential.
Their
application
extends
beyond
optoelectronics,
in
particular
organic
light-emitting
diodes
(OLEDs)
and
electrochemical
cells
(LECs),
include
also
photocatalysis,
sensing,
X-ray
scintillators.
From
the
perspective
of
sustainability,
earth-abundant
centers
preferred
rarer
second-
third-transition
series
elements,
thus
determining
a
reduction
costs
toxicity
but
without
compromising
overall
performances.
This
review
offers
an
overview
TADF
as
photoconversion
materials.
Particular
is
devoted
types
ligands
employed,
helping
design
novel
systems
with
enhanced
properties.
Green Chemistry,
Journal Year:
2024,
Volume and Issue:
26(8), P. 4600 - 4608
Published: Jan. 1, 2024
A
metal-free
and
catalyst-free
strategy
is
reported
to
achieve
N–H
insertions
by
coupling
N
-tosylhydrazones
with
diverse
amines
including
aminopyridines,
anilines,
aliphatic
amines,
other
nucleophiles
such
as
imidazoles
indoles.
