Pd₂₄Cu₁₂ Cages with Open Tripalladium Nodes for Selective Hydrogenation

Area of Science:

• Supramolecular Chemistry
• Coordination Chemistry
• Materials Science

Background:

• Metal-organic cages (MOCs) predominantly use Pd(II) nodes, limiting structural diversity.
• Developing novel palladium-based building blocks is crucial for expanding MOC functionalities and applications.
• Accessible metal sites within MOCs are key for catalytic activity.

Purpose of the Study:

• To introduce a new palladium cluster, {Pd3(SR')3[PR3]3}+ (Pd3), as a building unit for MOCs.
• To synthesize and characterize a novel Pd24Cu12 metal-organic cage using the Pd3 cluster.
• To evaluate the catalytic performance of the synthesized cage in hydrogenation reactions.

Main Methods:

• One-pot coassembly of the Pd3 cluster with Cu2 units.
• Structural characterization of the resulting Pd24Cu12 cage with a face-centered cubic architecture.
• Assessment of the cage's thermal and aerobic stability.
• Evaluation of catalytic activity and selectivity in azobenzene hydrogenation.

Main Results:

• Successful synthesis of a Pd24Cu12 cage featuring Pd3 nodes and Cu2 linkers.
• The cage exhibits exceptional thermal and aerobic stability due to its rigid framework and electronic communication.
• The Pd24Cu12 cage demonstrates high catalytic activity and selectivity in the hydrogenation of azobenzene.

Conclusions:

• The study introduces a novel class of catalytically active palladium nodes for MOC assembly.
• The developed Pd3 building block facilitates the creation of chemically diverse palladium-organic cages.
• The findings open avenues for exploring advanced cage-based catalysts in hydrogenation processes.