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

The photocatalytic performance of metal-organic frameworks (MOFs) depends on the synergistic regulation of metal node, organic ligand, and topological structure, yet improving the recyclability and scalability of heterogeneous catalysts remains a significant challenge. Herein, we demonstrate that metal precursor selection critically controls both framework topology and catalytic activity in copper-based MOFs. Using a newly designed hexapyridyl triptycene ligand and deliberately varying copper salts (CuCN vs CuCl₂), two topologically distinct MOFs, XJUM-1 and XJUM-2, with different pore size and photochemical properties were constructed. XJUM-2 exhibits a unique 6,4-connected 2-fold interpenetrated structure-unprecedented in cyanide-bridged systems-achieved through precise modulation of cyanide-bridge density. This structural control directly enhances charge separation, pore regularity, and catalytic performance. As a result, XJUM-2 delivers record-breaking activity for photocatalytic hydroboration of styrene (TOF = 86.4 h^-1, the highest among Cu-MOFs), alongside exclusive anti-Markovnikov selectivity, broad substrate scope (40 examples), and robust recyclability (>92% yield over 5 cycles). Our work transcends conventional ligand/metal-node engineering, demonstrating that metal precursor choice is a critical, previously overlooked handle for programming MOF topology and reactivity in organic transformations.