Copper(II)–Purine Complexes Encapsulated in NaY Zeolite

Abstract

Y-encapsulated CuII -purine complexes were synthesized, characterized and studied in the catalytic oxidation of cyclohexene. Encapsulation was achieved by ion-exchanging the complex from aqueous solutions containing both the purine ligand, 9-methyl-6-(methylamino)purine, and copper, in different pH, with a purine/Cu II molar ratio of 5:1. The resulting materials were characterized by surface analysis (XPS, SEM and XRD), chemical analysis, spectroscopic methods (EPR, FTIR and UV/Vis) and thermal analysis (TGA), which indicated that the Cu II -purine complexes were effectively encapsulated in NaY, most probably inside the supercages, without any modification of the morphology and structure of the zeo-

Encapsulation of manganese(III) complex in NaY nanoporosity for heterogeneous catalysis

“…[6,34] The SEM results also confirm that Soxhlet extraction is a suitable method for removing the species adsorbed on the external surface of zeolite. It is clear from the micrographs that during complex encapsulation the crystallite of support remains unchanged and there is no indication of the presence of any metal ions, ligand or complex on the surface.…”

“…In earlier studies, our group showed that the methodologies used for in situ encapsulation of the metal complexes in zeolites play an important role in the catalytic activity of these heterogeneous catalysts. [6,7] The localization of the active site is of crucial importance to heterogeneous catalyst behaviour. [8] Direct oxygen transfer to olefins is a well-established and popular route for the preparation of epoxides -valuable building blocks in synthetic organic chemistry.…”

Copper(II)–imida‐salen Complexes Encapsulated into NaY Zeolite for Oxidations Reactions

“…Figure 1 (A) represents a morphology typical of the faujasite zeolite. Analysis of the micrographs of NaY and the heterogeneous catalysts shows that there are no changes in the zeolite morphology or structure upon encapsulation of the complex 13,18. It appears from Figure 1 that Soxhlet extraction was efficient and the surface is completely washed out, which indicates the complete removal of uncoordinated ligands and the remaining metal complexes are physically adsorbed on to the external surface of the zeolite 19.…”

“…However, their mechanical stability could be advantageous during catalyst recycling and reuse 11,12. These catalysts are of interest for their applications in the oxidation of alkanes, alkenes and alcohols 13–15…”

Synthesis and Biological Activity of Some New Pyrazole Copper(II) Complexes

“…The evidence strongly suggests that the ultimate agent of DNA damage is some form of activated reduced oxygen, produced as a consequence of oxidation of bleomycin‐chelated iron(II) to iron(III) in a quaternary DNA‐bleomycin‐iron‐oxygen complex. On the other hand, copper(II) complexes are known to be effective DNA interaction and cleavage agents . These complexes are structurally well‐defined and thus suitable for mechanistic studies.…”