Two Complexes Based on Terpyridine Ligands: Efficient Carbon Dioxide Conversion and Fe ³⁺ Sensing

ABSTRACT Two new complexes {[Co( L )SO 4 (H 2 O) 3 ]·H 2 O} n ( 1 ), [Zn 3 ( L ) 2 Cl 6 ] n ( 2 ) ( L = 4′‐(4‐(1 H ‐1,2,4‐triazol‐1‐yl)phenyl)‐4,2′:6′,4″‐terpyridine) were successfully synthesized under solvothermal conditions by using the nitrogen‐rich ligand L . X‐ray single crystal diffraction results showed that complexes 1 and 2 have a one‐dimensional (1D) chain structure. Catalytic investigations showed that complex 1 could be used as a heterogeneous catalyst to efficiently catalyze the cycloaddition reaction of epoxides with CO 2 under solvent‐free conditions. Additionally, it exhibited good substrate universality and high reusability, maintaining the catalytic activity for at least five cycles without significant loss of efficiency. Fluorescence sensing experiments indicated that complex 2 can be used as a fluorescence turn‐off sensor for Fe 3+ with high selectivity, sensitivity, and low detection limits. Meanwhile, the mechanism study showed that the weak interaction and competitive absorption are the key factors of quenching.