Magnetic Antiaromaticity─Paratropicity─Does Not Necessarily Imply Instability
The Journal of Organic Chemistry,
Journal Year:
2023,
Volume and Issue:
88(20), P. 14831 - 14835
Published: Sept. 29, 2023
Magnetically
induced
ring
currents
are
a
conventional
tool
for
the
characterization
of
aromaticity.
Dia-
and
paratropic
thought
to
be
associated
with
stabilization
(aromaticity)
destabilization
(antiaromaticity),
respectively.
In
present
work,
I
have
questioned
validity
as
measure
antiaromaticity
among
monocyclic
hydrocarbons.
shown
that
while
reduced/oxidized
radical
ions
hydrocarbons
sustain
strong
currents,
they
often
gain
extra
via
cyclic
conjugation
compared
their
acyclic
counterparts.
Language: Английский
Mechanical performance and durability attributes of biodegradable natural fibre-reinforced composites—a review
Deleted Journal,
Journal Year:
2024,
Volume and Issue:
19(1)
Published: Dec. 26, 2024
Abstract
With
the
rising
awareness
about
impact
of
excessive
urbanization
on
environment,
alternative
and
more
eco-friendly
materials
such
as
natural
fibre-reinforced
composites
(NFRCs),
which
have
lower
embodied
energy,
can
be
considered
in
modern
application
ranging
from
construction
housing
to
urban
infrastructures
order
promote
concept
sustainable
development.
One
current
challenges
faced
by
material
engineers
is
develop
NFRCs
with
optimized
durability
performance
correspond
high
mechanical
attributes
during
their
service
lifetime
while
possessing
satisfactory
degradability
trait
disposal
phase.
This
proposed
review
study
principally
covered
state-of-the-art
progress
made
development
composite
advanced
biodegradable
NFRC.
In
first
section,
key
aspects
NFRC
fabrication
including
fibres
matrix
selection,
property-enhancing
treatment
for
influence
nanostructures
composites.
second
phase
this
review,
fibre-matrix
interaction
corresponding
physical
were
discussed.
The
typical
failure
modes
observed
outlined
means
improve
facture
toughness
proposed.
Finally,
third
section
comprised
degradation
assessment
components
NFRCs,
namely
fibre
reinforcement,
interface
sections.
Additionally,
disposing
similar
environment
was
assessed,
present-day
recycling
techniques
Further
research
performance,
traits
enumerated
will
unquestionably
use
integration
into
a
wider
range
engineering
applications
our
society.
Language: Английский
1,3-Dipolar Cycloadduct of Organometallic Allene with Dipolarophile─An Apparent Hückel–Möbius Aromatic Five-Membered Organometallic Carbene with Ambiphilic Reactivity
Organometallics,
Journal Year:
2024,
Volume and Issue:
43(13), P. 1411 - 1424
Published: June 25, 2024
1,3-Dipolar
cycloaddition
reaction
is
a
powerful
synthetic
for
the
generation
of
heterocycles
in
organic
chemistry.
However,
similar
reactions
organometallic
chemistry
are
limited.
Here,
we
report
structure
and
bonding
A-frame
μ-carbido
compounds
[M2(μ-C)Cl2(μ-dppm)2]
(1M,
M
=
Co,
Rh,
Ir),
their
with
dipolarophile,
dimethylacetylenediacetate
(DMAD),
resulting
cycloadduct
five-membered
bimetallic
carbene
complexes
[M2(μ-C)(μ-DMAD)Cl2(μ-dppm)2]
(2M).
The
geometrical
analysis
revealed
that
carbido
complex
1M
exhibits
linear
M–C–M
spine
planar
environment
around
metal
atom.
indicated
has
bisallylic
anionic
type
scenario.
Accordingly,
carbon
atom
highly
electrophilic
as
by
very
high
values
hydride
affinities.
allylic
delocalization
enforces
compound
to
act
1,3-dipole.
Hence,
these
undergo
stepwise
DMAD
2M.
center
shows
ambiphilic
reactivity
compared
nucleophilic
Arduengo
N-heterocyclic
carbene.
bimetalla
cyclic
ring
Hückel–Möbius
aromatic
having
10π
electrons,
which
contrast
6π
Hückel-type
delocalization.
Language: Английский