Photochromic Heterometallic Metal–Organic Framework as a Multifunctional Platform for Antibiotic Sensing and Sulfide Photooxidation

A highly stable heterometallic metal-organic framework (MOF), {[KCd(HL)]·DMF} (H₄L = 2,5-di(2",4"-dicarboxyphenyl)-1,4-difluoro-benzene), denoted as LCU-118 (LCU = Liaocheng University), was successfully synthesized via a solvothermal approach. Aqueous suspensions of LCU-118 exhibit remarkable photoluminescent discoloration upon continuous ultraviolet (UV) irradiation. Moreover, LCU-118 demonstrates the efficient detection of nitrofurantoin (NFT) and nitrofurazone (NZF) through a fluorescence quenching mechanism. Interestingly, the fluorescence quenched by NFT can be recovered to some extent after UV irradiation, which provides a reliable method for distinguishing NFT from NZF. Additionally, LCU-118 displays excellent catalytic activity toward the oxidation of methyl phenyl sulfide (MPS) at room temperature, offering a novel strategy for the efficient utilization of green energy. Mechanistic investigations reveal that the generation of superoxide radicals in the suspensions is involved in endowing LCU-118 with such multifunctional properties..