Experimental and Theoretical Evidence for Encapsulation and Tethering of 1,10-Phenanthroline Complexes of Fe, Cu, and Zn in Zeolite–Y

Abstract

Tris(1,10-phenanthroline) complexes of iron(II), copper(II), and zinc(II) have been encapsulated within the supercage of zeolite–NaY by the reaction of exchanged metal ion and flexible ligand that diffuses into the cavities. The hybrid material obtained has been characterized by elemental analysis (EDX), SEM, powder XRD, FTIR, UV–vis/DRS, cyclic voltammetry, and EPR techniques. The Fe and Cu complexes show electrochemical behavior in the presence of 0.1 M TBAP, whereas Zn complex gives electrochemical response only in the presence of H+ ion. This difference in electrochemical behavior of the complexes indicates an intrazeolite electron transport in the case of Fe and Cu phenanthroline complexes and an extrazeolite electron transport in the case of Zn complex anchored on the surface of zeolite–Y. The red shifting of UV–vis spectra and changes in redox properties of intrazeolite complexes in comparison to those of the neat complexes suggest that the zeolite matrix influences the electronic properties. This ...