Flexible ligand synthesis and characterization of a host (a copper(II) tetradentate Schiff base)/guest (zeolite NaY) nanocomposite material: An efficient and reusable catalyst for the selective hydroxylation of phenol

A copper(II) complex of 2,2′-(((butane-1,4-diylbis(oxy)) bis(2,1-phenylene))bis(azanylylidene)) bis(methanylylidene))diphenol (H₂L) was successfully encapsulated in the supercages of zeolite NaY by the flexible ligand method. The structure of this compound was identified by physico-chemical and spectroscopic methods. The selective hydroxylation of phenol was catalyzed using the free and encapsulated complexes. The results illustrated that the catalytic activity and stability of the complex was increased by encapsulation. Furthermore, the optimum reaction conditions were obtained. The kinetics of the reaction was also studied at different temperatures. The encapsulated complex is stable enough and it could be reused several times.