Immobilization of a metal complex in Y-zeolite matrix: synthesis, X-ray single-crystal, and catalytic activities of a copper (Schiff-base)-Y zeolite based hybrid catalyst

Abstract

A new zeolite-immobilized copper(II) complex catalyst has been prepared by entrapping [CuL] [LH₂ = N,N'-(1,1-dimethylethylene)bis(salicylaldiimine)] on NaY zeolite matrix. The reaction of Cu-NaY and molten LH₂ affords a green mass of crude catalyst that upon a treatment with CH₃CN gives a gray-colored hybrid catalyst (CuL-NaY). The prepared catalyst has been characterized by IR and UV-vis spectroscopic and EPR spectrometric measurements, TG-DTA analysis, powder X-ray diffraction, and surface-area measurements. To ascertain the structure of the immobilized complex, a single-crystal X-ray diffraction analysis of [CuL] was performed. Spectroscopic measurements showed that the green crude of CuL-NaY contains a penta- or hexa-coordinated copper(II) moiety, while the CuL-NaY catalyst contains a distorted square-planar [CuL] complex moiety. A remarkable catalytic activity of the prepared hybrid catalyst has been observed in oxidation reactions of 1-naphthol and norbornene.