Journal of the American Chemical Society,
Год журнала:
2024,
Номер
unknown
Опубликована: Ноя. 30, 2024
Dynamic
3D
covalent
organic
frameworks
(COFs)
have
shown
a
concerted
structural
transformation
upon
adaptive
guest
inclusion.
However,
the
origin
of
conformational
mobility
and
host–guest
adaptivity
remain
conjecture
pedal
motions
revolving
imine
linkages,
often
without
considering
steric
hindrance
from
interwoven
frameworks.
Here,
we
present
atomic-level
observation
rotational
translational
dynamics
in
single-crystal
COF-300
inclusion
various
molecules,
featuring
multiple
rotamers
linkages
switchable
interframework
noncovalent
interactions.
Specifically,
developed
diffusion
gradient
transimination
protocol
to
facilitate
growth
COF
single
crystals,
enabling
high-resolution
X-ray
diffraction
analysis.
We
uncovered
metastable
low-symmetry
intermediate
phases
contracted
expanded
during
evolution.
identified
torsion
angles
terephthalaldehyde
diimine
motifs
that
switch
anti-periplanar
syn-periplanar/anticlinal
conformations.
Moreover,
linkage
were
concurrent
with
tetraphenylmethane
units,
which
tend
form
quadruple
phenyl
embrace.
Such
allows
adapt
such
as
alcohols,
esters,
phenols,
diols,
double
linear,
herringbone,
zigzag
chains,
triple
helix,
tubular
alignments.
Quantitative
energy
analyses
revealed
dynamic
structure
transformations
are
not
arbitrary
but
follow
specific
pathways
resemble
protein
folding.
The
work
is
paving
way
developing
robust,
dynamic,
crystalline
molecular
sponges
for
studying
condensed
liquids
need
further
crystallization.
Journal of the American Chemical Society,
Год журнала:
2025,
Номер
unknown
Опубликована: Янв. 2, 2025
Furthering
the
field
of
synthetic
organic
chemistry
from
discrete
molecules
regime
to
extended
structure
regime,
covalent
frameworks
(COFs)
represent
a
new
genre
crystalline
porous
materials
featuring
designability
with
molecular-level
precision,
well-defined
porosity,
and
exceptional
stability
imparted
by
robust
linkages
reticulating
molecules.
The
topology
COFs
is
principal
feature
that
regulates
their
functionality
usability
for
emerging
technologies.
Profound
comprehension
network
topologies
maneuvering
them
toward
targeted
applications
are
crucial
advancing
realm
COF
research
developing
novel
functional
exciting
breakthroughs.
In
this
Perspective,
we
discuss
recent
pursuits
contributing
discovery
highly
connected
nets
having
topologies,
assess
key
challenges
achieving
such
offer
insights
into
current
scenario
future
directions.
Abstract
The
catalytic
conversion
of
CO
2
into
valuable
chemicals
using
metalized
covalent
organic
frameworks
(COFs)
as
catalysts
is
a
promising
method
for
reducing
atmospheric
levels.
Herein,
aldehyde‐amine
COF
(TAPT‐Tp)
at
room
temperature
and
pressure
their
metallized
results
synthesized,
Ni‐TAPT‐Tp
Ti‐TAPT‐Tp.
photocatalytic
indicate
that
the
to
reduction
rate
6182.5
µmol
g
−1
h
Ni‐TAPT‐Tp,
but
only
1615.4
Density
functional
theory
(DFT)
simulations
further
demonstrate
intermediates
*
,
COOH,
CO,
energy
consistently
lower
than
Ti‐TAPT‐Tp,
indicating
exhibits
superior
performance
RR.
This
work
provides
reference
optimizing
coordination
structure
M‐COFs
obtain
highly
active
selective
Catalysts,
Год журнала:
2025,
Номер
15(3), С. 237 - 237
Опубликована: Март 1, 2025
In
recent
years,
the
electrochemical
conversion
of
CO2
gasses
into
renewable
fuels
(e.g.,
ethylene,
ethanol,
and
propanol)
has
attracted
much
attention.
this
process,
electrocatalysts
play
a
crucial
role
in
accelerating
reduction
reaction
(CO2RR)
process.
review,
synthesis
C2+
products
from
was
investigated.
To
end,
various
classifications
such
as
metals,
metal
oxides,
alloys,
covalent
organic
frameworks
(COFs),
carbon-based
electrocatalysts,
metal–organic
(MOFs)
their
utilization
chemicals
were
fully
Also,
impact
factors
catalyst
stability,
temperature,
membrane
type,
pressure,
current
density,
pH,
type
electrolyte
on
CO2RR
process
to
generate
valuable
Moreover,
mechanism
for
producing
Furthermore,
limitations
future
perspective
surveyed.
Finally,
industrial
application
value-added
Based
our
investigation,
Cu
Cu2O-based
are
suitable
catalysts
products,
particularly
ethylene
ethanol.
Abstract
Cucurbit[
n
]urils
(abbreviated
as
Q[
]s
or
CB[
]s)
are
synthesized
through
the
condensation
of
formaldehyde
and
glycoluril
in
a
hydrochloric
acid
environment.
These
molecules
exhibit
three
distinctive
properties
concerning
their
charge
distribution:
neutral
internal
cavity,
positively
charged
outer
surface,
negatively
portal
carbonyl
oxygen
atoms.
unique
characteristics
facilitate
formation
supramolecular
frameworks
with
range
anions
metal
polyanions.
The
primary
focus
this
review
is
on
creation
anion‐induced
]‐based
self‐assemblies
exploring
potential
applications
ion
sequestration
release,
gas
adsorption,
well
development
fluorescence
probes.
Additionally,
concise
current
research
compounds
provided,
aiming
to
stimulate
future
advancements
field
innovative
framework
materials.
Journal of the American Chemical Society,
Год журнала:
2025,
Номер
unknown
Опубликована: Март 8, 2025
Here,
we
report
the
synthesis
of
a
3D
covalent
organic
framework
(COF),
COF-308,
with
unique
[4
+
2]
interpenetration.
Rather
than
inducing
unwanted
structure
dynamics
and
drastic
drop
in
surface
area,
this
interpenetration
mode
enhanced
structural
rigidity
achieved
desirable
area.
Such
an
was
unveiled
by
single
crystal
X-ray
diffraction
(SCXRD)
analysis
resolution
0.95
Å.
A
"face-to-face"
packing
tetrahedral
shaped
building
blocks
adjacent
frames
observed,
locking
slide
twisting
molecular
motion.
The
permanent
porosity
were
further
assessed
situ
small-angle
scattering
measured
along
gas
adsorption
desorption
processes.
distribution
gases
studied
across
entire
isotherm,
outlining
anisotropy
pores
within
COF-308.
anisotropy,
ideally
suited
for
storage
separation,
endowed
new
mode,
where
found
to
be
critical
control.
