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.
Inorganic Chemistry,
Journal Year:
2025,
Volume and Issue:
unknown
Published: Jan. 14, 2025
The
photophysical
properties
of
six
new
luminescent
tetrahedral
Zn(II)
complexes
are
presented
that
survey
two
electronic
donor
moieties
(phenolate
and
carbazolate)
three
acceptors
(pyridine,
pyrimidine,
pyrazine).
A
unique
ligand
based
on
an
o-terphenyl
motif
forms
eight-membered
chelate,
which
enhances
through-space
charge-transfer
(CT)
interactions
by
limiting
through-bond
conjugation
between
the
acceptor.
single
isomeric
product
was
obtained
in
yields
up
to
90%.
Single-crystal
X-ray
diffraction
structures
Zn
incorporating
either
show
complementary
interligand
π–π
interactions.
All
display
long-lived
luminescence
solid
state
consistent
with
emission
involving
triplet
state.
phenolate-based
evidence
CT
only
strongest
(pyrazinyl)
In
contrast,
all
carbazolate-based
thermally
activated
delayed
fluorescence
(TADF)
solution
state,
photoluminescent
quantum
39%.
These
ligands
represent
a
family
coordination
compounds
demonstrating
TADF/phosphorescent
expand
upon
elucidate
design
principles
pursuit
photoactive
earth-abundant
metal
complexes.
Asian Journal of Organic Chemistry,
Journal Year:
2025,
Volume and Issue:
unknown
Published: April 25, 2025
Abstract
Over
the
past
decades,
excessive
CO₂
emissions
have
caused
severe
environmental
problems,
primarily
global
warming
and
climate
change.
To
address
these
challenges,
researchers
developed
photocatalytic
approaches
to
convert
into
high‐value‐added
chemicals.
The
development
of
efficient,
green,
cost‐effective
reduction
systems
represents
a
crucial
step
toward
sustainable
energy
solutions.
However,
replacing
noble
metal‐based
photosensitizers,
which
are
widely
used
in
reduction,
with
more
alternatives
remains
challenging.
Thermally
activated
delayed
fluorescence
(TADF)
compounds
emerged
as
promising
organic
offering
high
quantum
efficiency,
long
lifetimes,
wide
redox
window.
Notably,
1,2,3,5‐Tetrakis(carbazol‐9‐yl)‐4,6‐dicyanobenzene
(4CzIPN),
prototypical
TADF
compound,
has
demonstrated
exceptional
performance
various
systems.
This
review
systematically
summarizes
recent
advances
TADF‐based
particularly
4CzIPN,
for
while
elucidating
their
underlying
reaction
mechanisms.
Angewandte Chemie,
Journal Year:
2023,
Volume and Issue:
135(16)
Published: Jan. 23, 2023
Abstract
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.
Journal of the American Chemical Society,
Journal Year:
2023,
Volume and Issue:
145(40), P. 22168 - 22175
Published: Sept. 28, 2023
Visible-to-ultraviolet
(UV)
triplet-triplet
annihilation
photochemical
upconversion
(TTA-UC)
has
gained
a
lot
of
attention
recently
due
to
its
potential
for
driving
demanding
high-energy
photoreactions
using
low-intensity
visible
light.
The
efficiency
this
process
rapidly
improved
in
the
past
few
years,
part
thanks
discovered
annihilator
compound
1,4-bis((triisopropylsilyl)ethynyl)naphthalene
(N-2TIPS).
Despite
beneficial
TTA-UC
characteristics,
success
N-2TIPS
context
is
not
yet
fully
understood.
In
work,
we
seek
elucidate
what
role
specific
type
and
number
substituents
naphthalene
compounds
play
achieve
characteristics
sought
after
TTA-UC.
We
show
that
substituent
attached
core
crucial
performance
as
an
annihilator.
More
specifically,
argue
choice
dictates
degree
sensitized
triplets
form
excimer
complexes
with
ground
state
annihilators
same
type,
which
competing
TTA.
addition
more
bulky
positively
impacts
upconverting
ability
by
impeding
formation
on
triplet
surface,
effect
enhanced
substituents.
presence
excimers
confirmed
from
transient
absorption
measurements,
rate
quantified,
showing
several
orders
magnitude
differences
between
different
derivatives.
These
insights
will
aid
further
development
solar
energy
applications
behavior
at
low
incident
powers
particular
significance.
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.
