Pore Engineering in Triptycene-Based Copper Metal-Organic Frameworks for High-Efficiency Photocatalytic Hydroboration

Area of Science:

• Materials Science
• Catalysis
• Supramolecular Chemistry

Background:

• Metal-organic frameworks (MOFs) are promising heterogeneous catalysts, but their recyclability and scalability are challenging.
• MOF performance relies on synergistic tuning of metal nodes, organic ligands, and topology.
• Controlling MOF topology and reactivity is crucial for advancing catalytic applications.

Purpose of the Study:

• To investigate the impact of metal precursor selection on copper-based MOF topology and photocatalytic performance.
• To design and synthesize novel MOFs with enhanced catalytic activity and recyclability.
• To demonstrate a new strategy for programming MOF structure and reactivity.

Main Methods:

• Synthesis of two distinct copper-based MOFs (XJUM-1 and XJUM-2) using a hexapyridyl triptycene ligand and different copper salts (CuCN vs. CuCl2).
• Structural characterization of the synthesized MOFs, revealing unique topological features.
• Evaluation of photocatalytic hydroboration of styrene using the synthesized MOFs, assessing activity, selectivity, and recyclability.

Main Results:

• Two topologically distinct MOFs, XJUM-1 and XJUM-2, were successfully synthesized.
• XJUM-2 exhibited an unprecedented 6,4-connected 2-fold interpenetrated structure.
• XJUM-2 demonstrated record-breaking photocatalytic hydroboration activity (TOF = 86.4 h-1) with high anti-Markovnikov selectivity and recyclability (>92% over 5 cycles).

Conclusions:

• Metal precursor choice is a critical factor in controlling MOF topology and catalytic performance.
• The developed MOF (XJUM-2) offers superior activity and selectivity for photocatalytic hydroboration.
• This work provides a new approach for designing efficient and recyclable MOF catalysts by manipulating metal precursor selection.