Sequential Energy\nand Electron Transfer in Metal–Organic\nFrameworks

This study presents the design and characterization of\na triad\nmetal–organic framework (MOF) system composed of pyrene, porphyrin,\nand phenyl-C<sub>61</sub>-butyric acid (PCBA) for efficient energy\nand electron transfer processes mimicking natural photosynthesis.\nThe triad MOF, synthesized through a mixed-ligand approach followed\nby postsynthetic modification, demonstrates sequential energy transfer\nfrom pyrene to porphyrin, followed by electron transfer to the PCBA\nacceptor. Time-resolved photoluminescence (TRPL) spectroscopy was\nemployed to investigate the dynamics of energy and charge transfer,\nrevealing fast interligand energy transfer and subsequent charge separation\nin the MOF structure. The PCBA-functionalized MOF (PCBA@nMLM) exhibited\na significantly enhanced photocatalytic performance compared to the\nnonfunctionalized counterpart, particularly in the selective aerobic\noxidation of sulfides to sulfoxides under visible light irradiation.\nThe enhanced photocatalytic activity is attributed to the prolonged\ncharge separation facilitated by the PCBA moieties, as confirmed by\nelectrochemical impedance spectroscopy (EIS) and transient photocurrent\nmeasurements. This work highlights the potential of MOF-based systems\nin artificial photosynthesis and other photocatalytic applications\nby effectively harnessing solar energy through optimized energy and\ncharge transfer mechanisms.