Journal of Polymer Science,
Год журнала:
2025,
Номер
unknown
Опубликована: Апрель 25, 2025
ABSTRACT
We
describe
the
synthesis
and
characterization
of
supramolecular
networks
based
on
charge‐assisted
hydrogen
bonding
interactions
guanidinium
oxyanion
functionalities.
Although
they
are
constructed
entirely
small‐molecule
components,
these
materials
display
properties
such
as
a
glass
transition
time‐
temperature‐dependent
viscoelastic
rheological
behavior.
These
can
be
tuned
by
choice
each
network
component:
T
g
varies
over
50°C
in
studied
networks,
relaxation
times
scaled
with
changes
to
.
However,
inherently
degradable
thermally
reversible
no
covalent
macromolecular
structure
is
formed.
Journal of the American Chemical Society,
Год журнала:
2021,
Номер
143(5), С. 2200 - 2206
Опубликована: Янв. 28, 2021
Carbazole/cyanobenzene
photocatalysts
promote
the
direct
isotopic
carboxylate
exchange
of
C(sp3)
acids
with
labeled
CO2.
Substrates
that
are
not
compatible
transition-metal-catalyzed
degradation–reconstruction
approaches
or
prone
to
thermally
induced
reversible
decarboxylation
undergo
incorporation
at
room
temperature
in
short
reaction
times.
The
radiolabeling
drug
molecules
and
precursors
[11C]CO2
is
demonstrated.
Polymer Reviews,
Год журнала:
2022,
Номер
62(4), С. 860 - 889
Опубликована: Янв. 31, 2022
The
global
environmental
issues
caused
by
plastic
incineration
are
continuously
increasing,
along
with
the
demand
for
polyethylene
terephthalate
(PET)—27
million
metric
tons
of
PET
was
demanded
in
2020.
Therefore,
recycling
has
emerged
as
core
circular
economy.
In
particular,
methods
categorized
into
two
pathways:
mechanical
and
chemical
recycling,
wherein
is
more
efficient
than
recycling.
However,
undergoes
heat-induced
degradations
during
such
reduction
molecular
weight
(MW)
viscosity.
feasible
required
to
overcome
challenges.
This
article
details
process
using
a
chain-extending
extrusion
method.
Accordingly,
various
chain
extenders
(CEs)
were
reviewed
identify
their
effects
on
recycled
(rPET)
properties
reactive
processes.
Moreover,
we
detailed
recent
progress
method
used
based
CEs
rPET
properties.
Journal of the American Chemical Society,
Год журнала:
2022,
Номер
144(47), С. 21658 - 21663
Опубликована: Ноя. 15, 2022
Superbase-derived
task-specific
ionic
liquids
(STSILs)
represent
one
of
the
most
attractive
and
extensively
studied
systems
in
carbon
capture
via
chemisorption,
which
obtained
CO2
uptake
capacity
has
a
strong
relationship
with
basicity
anions.
High
energy
input
desorption
side
reactions
caused
by
anions
are
still
unsolved
issues.
The
development
other
customized
STSILs
leveraging
an
alternative
driving
force
to
achieve
efficient
chemisorption/desorption
is
highly
desirable
yet
challenging.
In
this
work,
carbanion-derived
were
developed
for
chemisorption
carboxylic
acid
formation
pathway.
STSIL
deprotonated
malononitrile
molecule
([MN])
as
anion
exhibited
much
higher
than
derived
from
2-methylmalononitrile
([MMN]).
Notably,
trend
was
opposite
their
([MN]
<
[MMN]).
Detailed
characterization
products,
supported
density
functional
theory
simulations
spectra
calculations
reaction
energetics,
demonstrated
that
formed
upon
reacting
proton
transfer
[MN]-derived
but
not
case
[MMN]
due
lack
α-H.
preference
product
over
carboxylate
driven
extended
conjugation
among
central
sp2
carbon,
as-formed
acid,
two
nitrile
groups.
achievements
made
work
provide
design
principle
CO2-integrated
product.
JACS Au,
Год журнала:
2022,
Номер
2(6), С. 1234 - 1251
Опубликована: Июнь 7, 2022
Carbon-14
(14C)
is
a
gold
standard
technology
routinely
utilized
in
pharmaceutical
and
agrochemical
industries
for
tracking
synthetic
organic
molecules
providing
their
metabolic
safety
profiles.
While
the
state
of
art
has
been
dominated
decades
by
traditional
multistep
approaches,
recent
emergence
late-stage
carbon
isotope
labeling
provided
new
avenues
to
rapidly
access
carbon-14-labeled
biologically
relevant
compounds.
In
particular,
development
exchange
represented
fundamental
paradigm
change,
opening
way
unexplored
transformations.
this
Perspective,
we
discuss
developments
field
with
critical
assessment
literature.
We
subsequently
research
directions
future
challenges
within
evolving
field.
Green Chemistry,
Год журнала:
2023,
Номер
25(8), С. 3095 - 3102
Опубликована: Янв. 1, 2023
A
regiodivergent
electrochemical
defluorocarboxylation
of
gem
-difluorocyclopropanes
is
realized,
providing
access
to
branched
and
linear
carboxylated
monofluorinated
alkenes.
Angewandte Chemie International Edition,
Год журнала:
2020,
Номер
60(3), С. 1593 - 1598
Опубликована: Сен. 29, 2020
Abstract
The
direct
copolymerization
of
p
‐tosyl
isocyanate
(TSI)
with
epoxides,
initiated
by
onium
salts
in
the
presence
trialkylborane,
to
produce
polyurethanes
is
reported.
rate
and
(regio)selectivity
were
investigated
relation
trialkylborane
initiator
used.
Under
optimized
conditions
such
copolymerizations
have
been
successfully
performed
for
a
wide
range
including
ethylene
oxide,
propylene
1‐octene
cyclohexene
allyl
glycidyl
ether.
These
afford
new
category
polyurethanes,
clear
side
products
as
cyclic
oxazolidinone,
isocyanurate,
poly(isocyanate)
linkages.
experimental
used
this
work
are
compatible
those
organocatalytic
(co)polymerization
other
oxygenated
monomers
CO
2
,
holding
potential
their
terpolymerization
development
materials
unprecedented
properties.
Angewandte Chemie International Edition,
Год журнала:
2021,
Номер
60(24), С. 13559 - 13563
Опубликована: Апрель 7, 2021
Abstract
We
have
discovered
a
new
flex‐activated
mechanophore
that
releases
an
N‐heterocyclic
carbene
(NHC)
under
mechanical
load.
The
design
is
based
upon
NHC‐carbodiimide
(NHC‐CDI)
adducts
and
demonstrates
important
first
step
toward
designs
capable
of
further
downstream
reactivities.
Since
the
flex‐activation
non‐destructive
to
main
polymer
chains,
material
can
be
subjected
multiple
compression
cycles
achieve
iterative
increases
in
activation
percentage
mechanophores.
Two
different
NHC
structures
were
demonstrated,
signifying
potential
modularity
design.
Angewandte Chemie International Edition,
Год журнала:
2023,
Номер
62(36)
Опубликована: Апрель 19, 2023
In
contrast
to
stable
and
natural
abundant
carbon-12,
the
synthesis
of
organic
molecules
with
carbon
(radio)isotopes
must
be
conceived
optimized
in
order
navigate
through
hurdles
radiochemical
requirements,
such
as
high
costs
starting
materials,
harsh
conditions
radioactive
waste
generation.
addition,
it
initiate
from
small
cohort
available
C-labeled
building
blocks.
For
long
time,
multi-step
approaches
have
represented
sole
patterns.
On
other
side,
development
chemical
reactions
based
on
reversible
cleavage
C-C
bonds
might
offer
new
opportunities
reshape
retrosynthetic
analysis
radiosynthesis.
This
review
aims
provide
a
short
survey
recently
emerged
isotope
exchange
technologies
that
effective
opportunity
for
late-stage
labeling.
At
present,
strategies
relied
use
primary
easily
accessible
radiolabeled
C1-building
blocks,
dioxide,
monoxide
cyanides,
while
activation
principles
been
thermal,
photocatalytic,
metal-catalyzed
biocatalytic
processes.
Cell Reports Physical Science,
Год журнала:
2023,
Номер
4(8), С. 101510 - 101510
Опубликована: Июль 21, 2023
The
placement
of
main-group
functionalities
within
polymers
represents
a
strategy
to
access
wide
catalog
materials
but
is
limited
by
poor
understanding
the
catalyst
selection
criteria
and
polymerization
mechanism
when
moving
down
periodic
table.
Here,
we
study
series
new
heterobimetallic
carbon
dioxide
disulfide/epoxide
copolymerization
catalysts
that
allow
for
comparative
mechanistic
two
ring-opening
processes.
We
reveal
distinct
roles
each
metal
plays
are
preserved
from
disulfide,
maintaining
activity
selectivity
across
copolymerizations.
Experimental
computational
studies
show
can
be
understood
as
structurally
related
insertion
events
interlinked
central
oxygen/sulfur
scrambling
reaction
at
propagating
chain
end.
This
facilitates
synthesis
dioxide-/carbon
disulfide-/epoxide-derived
terpolymers
with
improved
degradability
over
parent
dioxide/epoxide
copolymers
low
levels
sulfur
incorporation.