Experimental and computational studies on zeolite-Y encapsulated iron(iii) and nickel(ii) complexes containing mixed-ligands of 2,2′-bipyridine and 1,10-phenanthroline

Abstract

Mixed ligand complexes of 2,2′-bipyridine and 1,10-phenanthroline with iron(III) and nickel(II) have been encapsulated into a zeolite cage by the reaction of zeolite exchanged metal ion with flexible ligands. The synthesized catalyst has been characterized by X-ray powder diffraction, scanning electron microscopy, BET surface area and pore volume analysis, FT-IR spectroscopy, thermo-gravimetric analysis and elemental analysis. Density functional theory calculations have been carried out on both neat complexes as well as metal complexes encapsulated into NaY zeolite to investigate changes in structural parameters, energies of the HOMO and LUMO, and global hardness and softness of the two metal complexes upon encapsulation into zeolite. Experimental results confirm successful formation of a mixed ligand complex of Fe(III) and Ni(II) inside the zeolite cage. Density functional theory calculations predict a higher reactivity of the zeolite encapsulated metal complexes compared to respective metal complexes. The zeolite encapsulated Fe(III) and Ni(II) complexes are found to be catalytically active toward the oxidation of 2-phenyl phenol (OPP).