Distinguishing packing configurations of molecular dimers using excited-state absorption peaks in two-dimensional electronic spectra
The Journal of Chemical Physics,
Год журнала:
2025,
Номер
162(17)
Опубликована: Май 1, 2025
Packing
conformations
of
molecular
aggregates
are
known
to
strongly
influence
the
locations
and
intensities
spectral
peaks.
Here,
we
develop
third-order
nonlinear
spectroscopy
signals
for
a
purely
electronic
model
dimer,
which
is
prototype
aggregate
system.
The
model-which
focuses
on
excited-state
absorption
(ESA)
pathways
in
two-dimensional
spectra-reveals
that
orientational
averaging
leads
diagnostic
ESA
peak
H-
J-dimers.
We
constructed
DNA-templated
dimers
cyanine
molecules
as
representative
systems
used
ultrabroadband
measurements
support
predicted
signatures
arising
from
theoretical
model.
Fitting
steady-state
spectra
supports
assigned
packing
conformations.
results
elucidate
how
peaks
can
be
conformation.
This
work
lays
foundation
future
studies
include
complicating
effects
vibronic
states
additional
levels.
Язык: Английский
Characterizing Absolute Orientations in DNA Self-Assembly of Single Molecules
The Journal of Physical Chemistry B,
Год журнала:
2025,
Номер
unknown
Опубликована: Май 14, 2025
DNA
self-assembly
of
single
molecules
(i.e.,
dyes)
with
deterministic
orientations
is
a
powerful
approach
for
engineering
molecular
excitons.
However,
current
determination
methods
the
dye
orientation
relative
to
do
not
account
plane,
which
missing
degree
freedom
needed
define
absolute
three-dimensional
orientations.
In
this
work,
we
combine
fluorescence-detected
linear
dichroism,
defocused
dipole
imaging,
and
point
accumulation
imaging
in
nanoscale
topography
(DNA-PAINT)
super-resolution
microscopy
determine
Cy5
dyes
host
duplexes,
includes
plane
orientation.
The
data
revealed
that
absorption
emission
dipoles
are
perpendicular
duplex,
mean
parallel
bases,
supports
notion
intercalate
between
base
pairs.
presented
methodology
will
inspire
investigation
controlling
arrangement
configurations
beyond
spontaneous
π-stacking
as
well
achieving
novel
dye-DNA
arrangements.
Язык: Английский