22 research outputs found
Heterogeneous formic acid production by hydrogenation of CO₂ catalyzed by Ir‐bpy embedded in polyphenylene porous organic polymers
Heterogeneous immobilized molecular catalysis has gained significant attention as a platform for creating more efficient and selective catalysts. A promising type of immobilized molecular catalysts are made from porous organic polymers (POPs) due to their high stability, porosity, and ability to mimic the catalytic activity and selectivity of homogeneous organometallic catalysts. These properties of the POP-based systems make them very attractive as heterogeneous catalysts for hydrogenation of CO2 to formate, where predominately homogeneous systems have been applied. In this study, five POPs were synthesized and assessed in the hydrogenation of CO2 where the active catalysts were made in-situ by mixing IrCl3 and the POPs. One of the Ir/POP catalysts provided a turn-over number (TON) >20,000, which is among the highest for POP-based systems. Thorough characterization (CO2- and N2-physisorption, TGA, CHN-analysis, XRD, XPS, SEM, STEM and TEM) was performed. Notably, the developed Ir/POP system also showed catalytic activity for the decomposition of formic acid into H2 enabling the use of formic acid as a renewable energy carrier
Aerobic Oxidation of Veratryl Alcohol to Veratraldehyde with Heterogeneous Ruthenium Catalysts
Size-selective aerobe oxidation by sinter stable gold nanoparticles embedded in zeolite crystals
Magnetic Archimedean Tessellations in Metal-Organic Frameworks
The
self-assembly of lanthanide ions with ditopic organic spacers
results in the formation of complex tiling patterns that mimic the
structural motifs of quasi-periodic 2D materials. The linking of trans-{LnI2}+ nodes (Ln = Gd, Dy)
by both closed-shell and anion radicals of 4,4′-bipyridine
affords rare examples of Archimedean tessellations in a metal–organic
framework. We furthermore demonstrate the occurrence of sizable magnetic
exchange interactions and slow relaxation of magnetization behavior
in a complex tessellation pattern. The implementation of Archimedean
tessellations in lanthanide(III) coordination solids couriers a strategy
to design elusive quasi-periodic metal–organic frameworks with
inimitable magnetic properties
Towards Frustration in Eu(II) Archimedean Tessellations
The solution self-assembly of trans-{EuI2} nodes and ditopic pyrazine or 4,4\u27-bipyridine leads to isoreticular 2D frameworks featuring the rare elongated triangular Archimedean tessellation pattern. The topology and the presence of intra-layer Eu(II)-Eu(II) antiferromagnetic interactions provide the prerequisites for geometrical spin frustration, which, due to the spin ground state degeneracy, is key for exotic magnetic phenomena such as enhanced magnetic refrigeration
Towards frustration in Eu(ii) Archimedean tessellations
This article is part of the themed collection: Chemical Communications HOT Articles 2023.Self-assembly of trans-{EuI2} nodes and ditopic ligands leads to isoreticular 2D frameworks featuring a rare, non-kagome Archimedean tessellation. The topology and intra-layer Eu(II)–Eu(II) antiferromagnetic interactions provide the prerequisites for geometrical spin frustration, which, due to the spin state degeneracy, is key for novel phenomena such as enhanced magnetic refrigeration.The authors acknowledge support from the VILLUM Foundation, the Independent Research Fund Denmark, ESS Lighthouses “SMART” and “Q-MAT”, MICINN (PID2021-124734OB-C21), DGA, Danscatt, and the ESRF (ID12 beamline).Peer reviewe