9 research outputs found
Electrostatic-Driven Self-Assembly of Janus-like Monolayer-Protected Metal Nanoclusters
The generation of controlled microstructures of functionalized
nanoparticles has been a crucial challenge in nanoscience and nanotechnology.
Efforts have been made to tune ligand charge states that can affect
the aggregation propensity and modulate the self-assembled structures.
In this work, we modeled zwitterionic Janus-like monolayer ligand-protected
metal nanoclusters (J-MPCs) and studied their self-assembly using
atomistic molecular dynamics and on-the-fly probability-based enhanced
sampling simulations. The oppositely charged ligand functionalization
on two hemispheres of a J-MPC elicits asymmetric solvation, primarily
driven by distinctive hydrogen bonding patterns in the ligand–solvent
interactions. Electrostatic interactions between the oppositely charged
residues in J-MPCs guide the formation of one-dimensional and ring-like
self-assembled superstructures with molecular dipoles oriented in
specific patterns. The pertinent atomistic insights into the intermolecular
interactions governing the self-assembled structures of zwitterionic
J-MPCs obtained from this work can be used to design a general strategy
to create tunable microstructures of charged MPCs
Electrostatic-Driven Self-Assembly of Janus-like Monolayer-Protected Metal Nanoclusters
The generation of controlled microstructures of functionalized
nanoparticles has been a crucial challenge in nanoscience and nanotechnology.
Efforts have been made to tune ligand charge states that can affect
the aggregation propensity and modulate the self-assembled structures.
In this work, we modeled zwitterionic Janus-like monolayer ligand-protected
metal nanoclusters (J-MPCs) and studied their self-assembly using
atomistic molecular dynamics and on-the-fly probability-based enhanced
sampling simulations. The oppositely charged ligand functionalization
on two hemispheres of a J-MPC elicits asymmetric solvation, primarily
driven by distinctive hydrogen bonding patterns in the ligand–solvent
interactions. Electrostatic interactions between the oppositely charged
residues in J-MPCs guide the formation of one-dimensional and ring-like
self-assembled superstructures with molecular dipoles oriented in
specific patterns. The pertinent atomistic insights into the intermolecular
interactions governing the self-assembled structures of zwitterionic
J-MPCs obtained from this work can be used to design a general strategy
to create tunable microstructures of charged MPCs
Electrostatic-Driven Self-Assembly of Janus-like Monolayer-Protected Metal Nanoclusters
The generation of controlled microstructures of functionalized
nanoparticles has been a crucial challenge in nanoscience and nanotechnology.
Efforts have been made to tune ligand charge states that can affect
the aggregation propensity and modulate the self-assembled structures.
In this work, we modeled zwitterionic Janus-like monolayer ligand-protected
metal nanoclusters (J-MPCs) and studied their self-assembly using
atomistic molecular dynamics and on-the-fly probability-based enhanced
sampling simulations. The oppositely charged ligand functionalization
on two hemispheres of a J-MPC elicits asymmetric solvation, primarily
driven by distinctive hydrogen bonding patterns in the ligand–solvent
interactions. Electrostatic interactions between the oppositely charged
residues in J-MPCs guide the formation of one-dimensional and ring-like
self-assembled superstructures with molecular dipoles oriented in
specific patterns. The pertinent atomistic insights into the intermolecular
interactions governing the self-assembled structures of zwitterionic
J-MPCs obtained from this work can be used to design a general strategy
to create tunable microstructures of charged MPCs
Electrostatic-Driven Self-Assembly of Janus-like Monolayer-Protected Metal Nanoclusters
The generation of controlled microstructures of functionalized
nanoparticles has been a crucial challenge in nanoscience and nanotechnology.
Efforts have been made to tune ligand charge states that can affect
the aggregation propensity and modulate the self-assembled structures.
In this work, we modeled zwitterionic Janus-like monolayer ligand-protected
metal nanoclusters (J-MPCs) and studied their self-assembly using
atomistic molecular dynamics and on-the-fly probability-based enhanced
sampling simulations. The oppositely charged ligand functionalization
on two hemispheres of a J-MPC elicits asymmetric solvation, primarily
driven by distinctive hydrogen bonding patterns in the ligand–solvent
interactions. Electrostatic interactions between the oppositely charged
residues in J-MPCs guide the formation of one-dimensional and ring-like
self-assembled superstructures with molecular dipoles oriented in
specific patterns. The pertinent atomistic insights into the intermolecular
interactions governing the self-assembled structures of zwitterionic
J-MPCs obtained from this work can be used to design a general strategy
to create tunable microstructures of charged MPCs
Electrostatic-Driven Self-Assembly of Janus-like Monolayer-Protected Metal Nanoclusters
The generation of controlled microstructures of functionalized
nanoparticles has been a crucial challenge in nanoscience and nanotechnology.
Efforts have been made to tune ligand charge states that can affect
the aggregation propensity and modulate the self-assembled structures.
In this work, we modeled zwitterionic Janus-like monolayer ligand-protected
metal nanoclusters (J-MPCs) and studied their self-assembly using
atomistic molecular dynamics and on-the-fly probability-based enhanced
sampling simulations. The oppositely charged ligand functionalization
on two hemispheres of a J-MPC elicits asymmetric solvation, primarily
driven by distinctive hydrogen bonding patterns in the ligand–solvent
interactions. Electrostatic interactions between the oppositely charged
residues in J-MPCs guide the formation of one-dimensional and ring-like
self-assembled superstructures with molecular dipoles oriented in
specific patterns. The pertinent atomistic insights into the intermolecular
interactions governing the self-assembled structures of zwitterionic
J-MPCs obtained from this work can be used to design a general strategy
to create tunable microstructures of charged MPCs
Cu(I)/<i>N,N</i>-Imine Ligand Catalyzed C(sp<sup>3</sup>)–C(sp) Coupling of Alkyl Bromides with Alkynes: Scope and Mechanistic Investigation
We
have developed an efficient Cu/N,N-bidentate imine ligand catalytic system for C(sp3)–C(sp)
coupling to obtain internal alkynes, di/trisubstituted allenes and
strained bridged cyclic lactams in moderate to excellent yields from
readily available alkyl(benzyl) bromides in one-pot transformation.
Density Functional Theory (DFT) assisted mechanistic study along with
control experiments support the involvement of bialkynylated copper
species which undergo single electron transfer (SET) with alkyl halides
to generate radical intermediate in the reaction. The N,N-bidentate imine ligand plays a vital role in
stabilization of intermediate copper complex and facilitates the product
formation
Divergent Approach to Highly Substituted Arenes via [3 + 3] Annulation of Vinyl Sulfoxonium Ylides with Ynones
Herein,
we report the divergent benzannulation for highly substituted
arenes using vinyl sulfoxonium ylides and ynones. The addition of
ynone at the Îł-position of vinyl sulfoxonium ylides leads to
dienyl sulfoxonium ylide that can undergo selective annulation under
different conditions to give m-terphenyls and parabens.
Moreover, control experiments and quantum chemical calculations reveal
two distinct reaction mechanisms for both annulations
Stereoselective <i>gem</i>-Difunctionalization of Diazo Compounds with Vinyl Sulfoxonium Ylides and Thiols via Metalloradical Catalysis
Multicomponent
reactions that involve carbenes with nucleophiles
and electrophiles have demonstrated broad applications in synthetic
chemistry. However, because of the high reactivity of transient carbenes,
reactions involving two carbene precursors with the nucleophile in
the presence of a metal catalyst remain unexplored. Herein, a three-component
stereoselective gem-difunctionalization of diazo
compounds with thiols and vinyl sulfoxonium ylide is disclosed via
Co(II)-based metalloradical catalysis. The key aspect of the present
strategy is to exploit the intrinsic difference in the reactivity
of vinyl sulfoxonium ylides and diazo compounds with thiol and metal
catalysts. The present Doyle–Kirmse rearrangement of a sulfonium
ylide involves a convergent assembly of two in situ-generated intermediates, such as allyl sulfide and α- metalloalkyl
radical complex, to provide expeditious access to tertiary sulfide
scaffolds. Combined experimental and quantum chemical calculations
unveil the intricate mechanism of this three-component reaction. Furthermore,
theoretical studies on noncovalent interactions of selectivity-determining
transition states explain the origin of the experimentally obtained
diastereoselectivity
Stereoselective <i>gem</i>-Difunctionalization of Diazo Compounds with Vinyl Sulfoxonium Ylides and Thiols via Metalloradical Catalysis
Multicomponent
reactions that involve carbenes with nucleophiles
and electrophiles have demonstrated broad applications in synthetic
chemistry. However, because of the high reactivity of transient carbenes,
reactions involving two carbene precursors with the nucleophile in
the presence of a metal catalyst remain unexplored. Herein, a three-component
stereoselective gem-difunctionalization of diazo
compounds with thiols and vinyl sulfoxonium ylide is disclosed via
Co(II)-based metalloradical catalysis. The key aspect of the present
strategy is to exploit the intrinsic difference in the reactivity
of vinyl sulfoxonium ylides and diazo compounds with thiol and metal
catalysts. The present Doyle–Kirmse rearrangement of a sulfonium
ylide involves a convergent assembly of two in situ-generated intermediates, such as allyl sulfide and α- metalloalkyl
radical complex, to provide expeditious access to tertiary sulfide
scaffolds. Combined experimental and quantum chemical calculations
unveil the intricate mechanism of this three-component reaction. Furthermore,
theoretical studies on noncovalent interactions of selectivity-determining
transition states explain the origin of the experimentally obtained
diastereoselectivity