Zeolite-encapsulated Cu(<scp>ii</scp>)–salen complexes for catalytic rhodamine B degradation

We successfully synthesized two copper complexes (CuL¹ and CuL²) with N₄-tetradentate salen ligands and encapsulated them within zeolite frameworks. Comprehensive characterization of both free and encapsulated complexes was performed using multiple analytical techniques. When employed as catalysts for H₂O₂-mediated rhodamine B degradation, CuL² demonstrated superior activity, which we attribute to the electropositive character of its imidazole moiety. Notably, encapsulation-induced modifications were observed in both the optical properties and catalytic performance of the complexes, arising from the constraints of the zeolite supercage structure. Under optimized conditions, the zeolite-encapsulated CuL¹-Y achieved 85% degradation efficiency, comparable to that of its free complex counterpart. Furthermore, the CuL¹-Y system exhibited excellent recyclability.