Photochem,
Journal Year:
2024,
Volume and Issue:
4(4), P. 462 - 473
Published: Oct. 31, 2024
The
excited
state
proton
transfer
(ESPT)
reaction
plays
a
crucial
role
in
DNA
defense
and
ON-OFF
proton-switching
molecular
devices.
o-Hydroxybenzaldehyde
(OHBA)
is
the
simplest
model-molecule
for
ESPT
reactions
where
transferred
from
OH
to
C=O
carbonyl
groups
by
photo-excitation.
In
present
study,
mechanism
of
OHBA
was
investigated
means
direct
ab
initio
dynamics
(AIMD)
method.
triplet
(T1)
OHBA,
OHBA(T1),
considered
as
OHBA.
dynamic
calculations
showed
that
fast
PT
occurred
at
T1
state.
time
calculated
be
34–57
fs
OHBA(T1).
spin
density
mainly
distributed
on
benzene
ring
(Bz)
zero.
gradually
Bz
function
surface.
When
larger
than
(at
=
35–43
fs),
rapidly
C=O.
localization
dominated
strongly
rate.
Next,
effects
residual
water
(H2O)
rate
were
using
OHBA-H2O
1:1-complexes
elucidate
H2O
rates
dependent
position
around
discussed
based
theoretical
results.
Advanced Science,
Journal Year:
2025,
Volume and Issue:
unknown
Published: Jan. 6, 2025
A
new
aggregation-induced
emission
(AIE)
luminogen
is
obtained
by
dimerizing
acridin-9(10H)-one
(Ac),
an
aggregation-caused
quenching
(ACQ)
effect
monomer
via
N─N
bond
and
forming
9H,9'H-[10,10'-biacridine]-9,9'-dione
(DiAc)
with
D2d
symmetry.
The
of
DiAc
in
solution
ascribed
to
the
enhanced
basicity
promoting
hydrogen
bonding
then
a
abstraction
(HA)
reaction
and/or
unallowed
transition
frontier
orbitals
same
symmetry
facilitating
intersystem
crossing.
It
found
that
emissive
Ac
one
product
non-emissive
HA
activated
UV
irradiation.
By
exploiting
AIE
properties
DiAc,
photolithographic
patterning
demonstrated
paper
wetted
solution.
Chinese Journal of Chemistry,
Journal Year:
2025,
Volume and Issue:
unknown
Published: Jan. 16, 2025
Comprehensive
Summary
Excited‐state
intramolecular
proton
transfer
(ESIPT)
involves
photochemical
tautomerization
between
two
excited
states
(E*
and
K*)
via
transfer.
Developing
polymer
photochromism
based
on
the
of
organic
ESIPT
molecules
has
been
rarely
reported.
We
report
molecule
HBT‐2OH
exhibits
concentration‐dependent
photochromic
behavior
in
a
polyurethane
(PU)
network.
At
low
concentrations,
primarily
exists
trans
‐enol
configuration
without
OH···N
hydrogen
bonds
PU,
emitting
blue
fluorescence
at
~464
nm
(enol
emission).
Upon
UV
irradiation,
dihedral
angle
donor
acceptor
twists
to
form
an
H‐bond,
converting
cis
resulting
with
pale
yellow
~603
(keto
The
effect
HBT‐2OH@PU
diminishes
high
concentrations
due
that
aggregation
favors
form.
Control
HBT,
HBO‐2OH
,
HBI‐2OH
show
no
confirming
ethanolyl
branches
OH···S
stabilize
.
Incorporating
these
into
PMMA
PCL
networks
demonstrates
increased
free
volume
smaller
aggregates
enhance
by
reducing
resistance
twisting.
Density
functional
theory
(DFT)
calculations
further
confirm
stable
heteroatomic
(OH···S)
exist
This
study
offers
new
theoretical
insights
opens
avenues
for
research
materials.
ACS Omega,
Journal Year:
2025,
Volume and Issue:
unknown
Published: Jan. 29, 2025
Herein,
we
report
an
efficient
mechanochemical
synthesis
of
α,α-amino
thioketones
involving
a
one-pot,
three-component
milling
2-oxo
aldehydes,
amines,
and
thiols.
Unlike
previous
methods,
this
protocol
does
not
require
any
catalyst
or
oxidizing
additive.
The
reaction
proceeds
through
the
thiolation
in
situ
formed
α-imino
ketones
by
liquid-assisted
grinding.
We
have
successfully
extended
to
synthesizing
benzothiazoles,
thiazoles,
quinoxalines,
demonstrating
its
efficiency
potential
field.
Importantly,
shown
gram-scale
synthesis,
synthetic
applications,
substrate
scope
protocol,
instilling
confidence
practicality.
The Journal of Physical Chemistry A,
Journal Year:
2024,
Volume and Issue:
128(20), P. 4020 - 4029
Published: May 14, 2024
In
this
study,
we
systematically
explored
the
impact
of
varying
number
thiophene
groups
on
hydrogen
bond
interaction
and
excited-state
intramolecular
proton-transfer
(ESIPT)
processes
in
flavonoid
derivatives
(STF,
DTF,
TTF)
using
density
functional
theory
time-dependent
methods.
Initially,
a
thorough
analysis
optimized
geometric
structures
revealed
that
S1
state
is
enhanced
gradually
weakened
as
increases.
To
gain
deeper
understanding
interaction,
topological
analysis,
region
indicator
scatter
plots,
isosurface
plots
were
employed.
These
images
provide
further
insights
align
with
structural
analysis.
Additionally,
observed
red-shift
electronic
spectra
(absorption
fluorescence
spectra),
which
primarily
attributed
to
narrowing
energy
gap
between
highest
occupied
molecular
orbital
lowest
unoccupied
orbital,
elucidated
by
frontier
orbitals.
Furthermore,
combined
hole–electron
distribution
transition
matrix
heat
map
shows
electron
excitation
involves
unidirectional
charge-transfer
mechanism.
end,
conducting
relaxed
potential
curve
scans,
found
an
increase
elevates
barrier
for
ESIPT,
making
it
more
challenging
reaction.
summary,
our
study
underscores
vital
effect
thiophene-substituted
numbers
modulating
ESIPT
process,
able
valuable
design
synthesis
desired
organic
fluorescent
probes
future.
The Journal of Physical Chemistry A,
Journal Year:
2024,
Volume and Issue:
128(34), P. 7084 - 7089
Published: Aug. 14, 2024
Gas
phase
excited-state
quantum
wavepacket
dynamics
simulations
of
the
thiotropolone
demonstrate
ultrafast
triplet
formation
upon
photoexcitation
to
dipole-allowed
S2
state.
The
dominant
relaxation
pathway
S2–T4
intersystem
crossing,
facilitated
by
strong
spin–orbit
coupling
and
narrow
energy
gap,
competes
with
S1/S3
internal
conversion.
populated
in
T4
via
former
decays
lower
states.
Computed
potential
profiles
suggest
proton
transfer
S2,
which
might
compete
conversion
crossing.
nonadiabatic
population
from
states
enables
latter
states,
resulting
multiple
pathways.
Experimental
investigations
are
necessary
shed
light
on
complex
photodynamics
thiotropolone.
