Direct synthesis of functionalized PCN-333 via linker design for Fe³⁺ detection in aqueous media

A new luminescent mesoporous metal-organic framework (PCN-604) was successfully synthesized from trimetric clusters, Al3(O)(CH3COO)6, and pyridine-based tritopic linkers, 4,4',4''-(pyridine-2,4,6-triyl)tribenzoate (PTB), via a solvothermal reaction. The MOF with an MTN topology possesses remarkable aqueous and thermal stabilities. Due to the efficient binding sites rendered by the pyridyl-based linkers, PCN-604 shows a fast fluorescence response towards trace amounts of Fe3+ ions in water in a fluorescence-quenching mode. The Stern-Volmer quenching constant is calculated to be 8.53 × 103 M-1 and the limit of detection is 6.2 μM, which convincingly demonstrate the ability of the MOF for Fe3+ detection.