Combination
of
experimental
data
and
results
DFT
calculations
indicates
that
the
catalytic
activity
chalconium
halonium
salts
served
as
sigma-hole
donating
organocatalysts
cannot
be
clearly
estimated
via
analysis
electrostatic
potential
on
catalysts’
sigma-holes
values
catalyst•••TS
intermolecular
interactions,
such
polarization
effects,
charge
transfer,
or
covalency
bonding.
Moreover,
real
effect
might
not
correlate
well
with
Gibbs
free
energies
activation
reactions,
because
solvation
effects
other
competitive
binding
processes
play
at
least
same
even
more
important
role
in
catalysis.
It
was
showed
present
work,
either
can
lead
to
increase
equilibrium
concentration
reactive
catalyst•••electrophile
associates
thus
accelerating
reaction
brings
favorable
generation
catalyst•••nucleophile
species
resulting
suppression
organocatalyst.
Angewandte Chemie,
Год журнала:
2023,
Номер
135(26)
Опубликована: Апрель 26, 2023
Abstract
Exploiting
non‐covalent
interactions
to
catalyze
challenging
ionic
polymerizations
is
an
ambitious
goal
but
in
its
infancy.
We
recently
demonstrated
anion‐binding
catalysis
as
effective
methodology
enable
living
cationic
polymerization
(LCP)
of
vinyl
ethers
environmentally
benign
manner.
Here,
we
further
elucidate
the
structure‐reactivity
relationships
elaborately
designed
seleno‐cyclodiphosph(V)azanes
catalysts
and
roles
by
a
combined
theoretical
DFT
study
experimental
study.
The
investigation
suggests
that
distinct
cis
‐cyclodiphosph(V)azane
framework
with
“selenium
effect”
electron‐withdrawing
3,5‐(CF
3
)
2
‐Phenyl
substitution
pattern
catalyst
enables
critical
contribution
accessing
excellent
stability,
anion
affinity
solubility
under
conditions.
Thus,
could
leverage
precisely
control
reversible
transient
dormant‐active
species
equilibrium,
allowing
it
dynamically
bind,
recognize
pre‐organize
propagating
monomer,
thereby
facilitating
efficient
chain
propagation
minimizing
irreversible
transfer
events
mild
more
in‐depth
understanding
mechanism
for
catalytic
LCP
reported
herein
should
help
guide
future
design
extend
this
concept
broader
systems
where
serve
crucial
intermediates.
Journal of Polymer Science,
Год журнала:
2023,
Номер
61(21), С. 2655 - 2664
Опубликована: Авг. 14, 2023
Abstract
The
cationic
polymerization
of
p
‐methoxystyrene
(pMOS)
was
carried
out
at
25°C
using
pMOS·HCl
and
Sb(C
6
F
5
)
3
.
Under
the
condition
[pMOS·HCl]:[Sb(C
]:[pMOS]
=
10:10:500
in
mM
concentration,
CH
CN/CH
2
Cl
(3/1
volume
ratio)
homogeneously
proceeded
giving
rise
to
poly(pMOS)
with
M
n
5800
w
/
1.50.
Based
on
monomer
consumption
rate,
catalytic
activity
increased
order
(5.9
×
10
−1
h
>
Te(C
(2.0
IC
(1.0
−2
).
In
presence
Bu
4
NCl
(0.02
equivalent
relative
),
molecular
weight
distribution
became
narrower
(
1.23),
but
MALDI‐TOF/MS
implied
chain
transfer
reactions.
On
other
hand,
pMOS
[MeSbPh
][TEPB]
combined
resulted
better
controllability
(calculated
6100
theoretical
6300),
where
reactions
were
decreased
as
confirmed
by
analysis.
[SbPh
][OTf]
exhibited
a
activity.
[EtOCOCH
SbPh
electron‐withdrawing
ester
group
showed
highest
(monomer
conversion
reached
91%
8
h)
while
maintaining
narrow
1.27).
‐Methylstyrene
styrene
also
polymerized
catalyst
][TEPB],
although
not
controlled.
Macromolecules,
Год журнала:
2024,
Номер
57(7), С. 3358 - 3367
Опубликована: Март 22, 2024
The
electrochemical
oxidation
behavior
of
organotellurium
compounds
(DAnT,
POxT,
PThT,
and
PAzT)
the
structure–property
relationships
resulting
cationic
species
were
evaluated
by
cyclic
voltammetry
electro
spin
resonance
measurements
density
functional
theory
calculations.
[POxT2]2+
obtained
from
POxT
was
found
to
have
a
highly
active
chalcogen
bonding
(ChB)
potency
as
evidenced
large
Vs,max
value
(186.4
kcal·mol–1).
While
neutral
has
no
catalytic
activity,
electrochemically
generated
applying
an
potential
at
0.68
V
vs
Ag/Ag+
can
activate
carbon–chlorine
bond
propagating
chain
ends
p-methylstyrene
(pMeS)
through
ChB
interaction,
in
complete
monomer
conversion
0
°C
1
h
give
poly(pMeS)
with
theoretical
molecular
weight
(Mn
=
6100)
relatively
narrow
distribution
(Mw/Mn
1.49).
PAzT
could
not
bring
about
polymerization
pMeS,
but
p-methoxystyrene
(pMOS)
higher
ability
smoothly
consumed
afford
poly(pMOS)
having
Mn
9400
Mw/Mn
1.94.
counteranion
supporting
electrolyte
influenced
behavior;
namely,
application
Bu4NPF6
induced
controlled
pMeS
polymer
be
determined
feed
ratio.
Importantly,
control
over
growth
achieved
reversibly
switching
direction
current
flow
cell
between
(ON
state)
−0.30
(OFF
state).
ACS Catalysis,
Год журнала:
2023,
Номер
13(23), С. 15505 - 15515
Опубликована: Ноя. 16, 2023
Halogen-bond-based
organocatalysis
is
a
promising
alternative
to
extensively
explored
hydrogen-bond-based
catalysis.
This
paper
presents
comprehensive
theoretical
investigation
of
the
structural
and
electronic
properties
σ-hole,
as
well
computational
design
series
electronically
activated
monodentate
bidentate
iodine
benzimidazolium
achiral
donor
systems,
inspired
by
experimental
papers
published
in
past
decade.
The
aforementioned
activation
modes
are
compared,
mechanistic
details
reaction
discussed.
A
computational
analysis
of
possible
routes
cooperative
catalysis
involving
hydrogen
bond
donating
thiourea
and
halogen
organocatalysts
has
been
carried
out
at
the
M06-2X/SDD
level
theory
using
solvation
model
based
on
density
(SMD).
For
systems
2-iodoimidazolium
or
iodonium
salt
derivatives,
previously
suggested
route
including
sequential
electrophilic
activation
a
reaction
electrophile
via
XB-activated
HB
donor
was
ruled
out.
Polymer Chemistry,
Год журнала:
2024,
Номер
15(11), С. 1062 - 1069
Опубликована: Янв. 1, 2024
The
stereoregularity
and
molecular
weight
of
poly(isobutyl
vinyl
ether)
was
simultaneously
controlled
by
TADDOL/TiCl
4
initiating
systems
with
various
aryl
substituents
on
TADDOL.
The
combination
of
experimental
data
and
results
DFT
calculations
indicates
that
the
catalytic
activity
chalconium
halonium
salts
serving
as
sigma-hole
donating
organocatalysts
cannot
be
clearly
estimated
via
analysis
electrostatic
potential
on
catalysts’
sigma-holes
values
catalyst•••TS
intermolecular
interactions,
such
polarization
effects,
charge
transfer,
or
covalency
bonding.
Moreover,
real
effect
might
not
correlate
well
with
Gibbs
free
energy
activation
reactions,
because
solvation
effects
other
competitive
binding
processes
play
at
least
an
equal
even
more
important
role
in
catalysis.
It
was
shown
present
work
can
either
lead
to
increase
equilibrium
concentration
reactive
catalyst•••electrophile
associates,
thus
accelerating
reaction,
brings
favorable
generation
catalyst•••nucleophile
species
resulting
suppression
organocatalyst.
A
computational
analysis
of
possible
routes
cooperative
catalysis
involving
hydrogen
bond
(HB)
and
halogen
(XB)
donating
organocatalysts
has
been
carried
out.
Previously
suggested
route
including
electrophilic
activation
HB
donor
by
XB
was
ruled
out
but
a
path
double
reaction
electrophile
its
simultaneous
association
with
the
species
confirmed
DFT
calculations.
Halogen-bond-based
organocatalysis
is
a
promising
alternative
to
the
extensively
explored
halogen-bond-based
catalysis.
This
paper
presents
comprehensive
theoreti-
cal
investigation
of
structural
and
electronic
properties
σ-hole,
as
well
computational
design
series
electronically
activated
monodentate
bidentate
iodine
benzimidazolium
achiral
donor
systems,
inspired
by
experimental
com-
putational
papers
published
in
last
decade.
The
aforementioned
activation
modes
are
compared,
mechanistic
details
reaction
discussed.
