4 research outputs found
Localized Conversion of MetalāOrganic Frameworks into Polymer Gels via Light-Induced Click Chemistry
The
ability to control the structure and topology of polymer networks,
both on macroscopic and molecular levels, is crucial for optimizing
their performance. Here we describe a novel type of network polymer,
which is synthesized via conversion of a highly ordered metalāorganic
framework (MOF) template into a polymer gel. The synthesis is performed
using light-induced and metal-free thiolāene click chemistry.
The use of light-triggered reactions in combination with photomasks
or other photopatterning techniques allows the reaction to be locally
confined and thereby structuring the network polymer on a macroscopic
level. The potential to vary and exactly adjust the parameters within
the polymer network (including exact network topology on the nanometer
scale as well as the macroscopic morphology) combined with the ability
to further functionalize their surfaces or incorporate guest molecules
allows their targeted design for potential applications in catalysis
and optoelectronics as well as their use as a novel biomaterial
RhodiumāOrganic Cuboctahedra as Porous Solids with Strong Binding Sites
The upbuilding of
dirhodium tetracarboxylate paddlewheels into porous architectures
is still challenging because of the inertness of equatorial carboxylates
for ligand-exchange reaction. Here we demonstrate the synthesis of
a new family of metalāorganic cuboctahedra by connecting dirhodium
units through 1,3-benzenedicarboxylate and assembling cuboctahedra
as porous solids. Carbon monoxide and nitric oxide were strongly trapped
in the internal cavity thanks to the strong affinity of unsaturated
axial coordination sites of dirhodium centers
RhodiumāOrganic Cuboctahedra as Porous Solids with Strong Binding Sites
The upbuilding of
dirhodium tetracarboxylate paddlewheels into porous architectures
is still challenging because of the inertness of equatorial carboxylates
for ligand-exchange reaction. Here we demonstrate the synthesis of
a new family of metalāorganic cuboctahedra by connecting dirhodium
units through 1,3-benzenedicarboxylate and assembling cuboctahedra
as porous solids. Carbon monoxide and nitric oxide were strongly trapped
in the internal cavity thanks to the strong affinity of unsaturated
axial coordination sites of dirhodium centers
Integration of Porous Coordination Polymers and Gold Nanorods into CoreāShell Mesoscopic Composites toward Light-Induced Molecular Release
Besides
conventional approaches for regulating in-coming molecules
for gas storage, separation, or molecular sensing, the control of
molecular release from the pores is a prerequisite for extending the
range of their application, such as drug delivery. Herein, we report
the fabrication of a new porous coordination polymer (PCP)-based composite
consisting of a gold nanorod (GNR) used as an optical switch and PCP
crystals for controlled molecular release using light irradiation
as an external trigger. The delicate coreāshell structures
of this new platform, composed of an individual GNR core and an aluminum-based
PCP shell, were achieved by the selective deposition of an aluminum
precursor onto the surface of GNR followed by the replication of the
precursor into aluminum-based PCPs. The mesoscopic structure was characterized
by electron microscopy, energy dispersive X-ray elemental mapping,
and sorption experiments. Combination at the nanoscale of the high
storage capacity of PCPs with the photothermal properties of GNRs
resulted in the implementation of unique motion-induced molecular
release, triggered by the highly efficient conversion of optical energy
into heat that occurs when the GNRs are irradiated into their plasmon
band. Temporal control of the molecular release was demonstrated with
anthracene as a guest molecule and fluorescent probe by means of fluorescence
spectroscopy