4 research outputs found
Molecular Marriage through Partner Preferences in Covalent Cage Formation and Cage-to-Cage Transformation
Unprecedented self-sorting of three-dimensional purely
organic
cages driven by dynamic covalent bonds is described. Four different
cages were first synthesized by condensation of two triamines and
two dialdehydes separately. When a mixture of all the components was
allowed to react, only two cages were formed, which suggests a high-fidelity
self-recognition. The issue of the preference of one triamine for
a particular dialdehyde was further probed by transforming a non-preferred
combination to either of the two preferred combinations by reacting
it with the appropriate triamine or dialdehyde
Molecular Marriage through Partner Preferences in Covalent Cage Formation and Cage-to-Cage Transformation
Unprecedented self-sorting of three-dimensional purely
organic
cages driven by dynamic covalent bonds is described. Four different
cages were first synthesized by condensation of two triamines and
two dialdehydes separately. When a mixture of all the components was
allowed to react, only two cages were formed, which suggests a high-fidelity
self-recognition. The issue of the preference of one triamine for
a particular dialdehyde was further probed by transforming a non-preferred
combination to either of the two preferred combinations by reacting
it with the appropriate triamine or dialdehyde
Molecular Cage Impregnated Palladium Nanoparticles: Efficient, Additive-Free Heterogeneous Catalysts for Cyanation of Aryl Halides
Two shape-persistent covalent cages
(<b>CC1</b><sup><b>r</b></sup> and <b>CC2</b><sup><b>r</b></sup>) have
been devised from triphenyl amine-based trialdehydes and cyclohexane
diamine building blocks utilizing the dynamic imine chemistry followed
by imine bond reduction. The cage compounds have been characterized
by several spectroscopic techniques which suggest that <b>CC1</b><sup><b>r</b></sup> and <b>CC2</b><sup><b>r</b></sup> are [2+3] and [8+12] self-assembled architectures, respectively.
These state-of-the-art molecules have a porous interior and stable
aromatic backbone with multiple palladium binding sites to engineer
the controlled synthesis and stabilization of ultrafine palladium
nanoparticles (PdNPs). As-synthesized cage-embedded PdNPs have been
characterized by transmission electron microscopy (TEM), scanning
electron microscopy (SEM), and powder X-ray diffraction (PXRD). Inductively
coupled plasma optical emission spectrometry reveals that <b>Pd@CC1</b><sup><b>r</b></sup> and <b>Pd@CC2</b><sup><b>r</b></sup> have 40 and 25 wt% palladium loading, respectively. On the
basis of TEM analysis, it has been estimated that as small as ∼1.8
nm PdNPs could be stabilized inside the <b>CC1</b><sup><b>r</b></sup>, while larger <b>CC2</b><sup><b>r</b></sup> could stabilize ∼3.7 nm NPs. In contrast, reduction of palladium
salts in the absence of the cages form structure less agglomerates.
The well-dispersed cage-embedded NPs exhibit efficient catalytic performance
in the cyanation of aryl halides under heterogeneous, additive-free
condition. Moreover, these materials have excellent stability and
recyclability without any agglomeration of PdNPs after several cycles
Molecular Cage Impregnated Palladium Nanoparticles: Efficient, Additive-Free Heterogeneous Catalysts for Cyanation of Aryl Halides
Two shape-persistent covalent cages
(<b>CC1</b><sup><b>r</b></sup> and <b>CC2</b><sup><b>r</b></sup>) have
been devised from triphenyl amine-based trialdehydes and cyclohexane
diamine building blocks utilizing the dynamic imine chemistry followed
by imine bond reduction. The cage compounds have been characterized
by several spectroscopic techniques which suggest that <b>CC1</b><sup><b>r</b></sup> and <b>CC2</b><sup><b>r</b></sup> are [2+3] and [8+12] self-assembled architectures, respectively.
These state-of-the-art molecules have a porous interior and stable
aromatic backbone with multiple palladium binding sites to engineer
the controlled synthesis and stabilization of ultrafine palladium
nanoparticles (PdNPs). As-synthesized cage-embedded PdNPs have been
characterized by transmission electron microscopy (TEM), scanning
electron microscopy (SEM), and powder X-ray diffraction (PXRD). Inductively
coupled plasma optical emission spectrometry reveals that <b>Pd@CC1</b><sup><b>r</b></sup> and <b>Pd@CC2</b><sup><b>r</b></sup> have 40 and 25 wt% palladium loading, respectively. On the
basis of TEM analysis, it has been estimated that as small as ∼1.8
nm PdNPs could be stabilized inside the <b>CC1</b><sup><b>r</b></sup>, while larger <b>CC2</b><sup><b>r</b></sup> could stabilize ∼3.7 nm NPs. In contrast, reduction of palladium
salts in the absence of the cages form structure less agglomerates.
The well-dispersed cage-embedded NPs exhibit efficient catalytic performance
in the cyanation of aryl halides under heterogeneous, additive-free
condition. Moreover, these materials have excellent stability and
recyclability without any agglomeration of PdNPs after several cycles