Copper(II) complexes of embelin and 2-aminobenzimidazole encapsulated in zeolite Y-potential as catalysts for reduction of dioxygen

Abstract

Copper(II) complexes of two biologically important ligands, viz., embelin (2,5-dihydroxy-3-undecyl-2,5-cyclohexadien 1,4-dione) and 2-aminobenzimidazole were entrapped in the cages of zeolite Y by the flexible ligand method. The capability of these compounds in catalyzing the reduction of oxygen (industrially known as deoxo reaction) was explored and the results indicate an enhancement of the catalytic properties from that of the simple copper ion exchanged zeolite. These point to the ability of the ligands in enhancing the oxygen binding capability of the metal ion. Elemental analyses, Fourier transform infrared (FTIR), diffuse reflectance and EPR spectral studies, magnetic susceptibility measurements, TG, surface area analyses and powder X-ray diffraction studies were used in understanding the presence, composition and structure of the complexes inside the cages. The study also reveals the increased thermal and mechanical stability of the complexes as a result of encapsulation.

A catalytic process for the selective oxidation of alcohols by copper (II) complexes

“…The observed low A values (Table 3) of the order of 132-160 × 10 −4 cm −1 are also consistent with a typical monomeric distorted five coordinated structure [32]. However the quotient g /A is helpful for indexing and identifying a distortion towards five coordinated structure [33,34]. The quotient should range from 145 to 175 cm −1 for a regular five coordinated structure and the observed results (140-170 cm −1 ) are indicative of square-pyramidal geometry.…”

Adsorption of [AuCl4]- on Iron Sand Magnetic Material Coated with Aminobezimidazol Modified Silica

“…The evidence of silica coated on MM surface is identified by the presence of Si-O-Si bending vibration at 1087 cm -1 with high intensity compare to spectra of MM [10]. Functionalization of aminobenzimidazole groups to silica are verified by C=C stretching vibration of aromatic benzene at 1481 cm -1 and C=C stretching vibration of imidazole ring at 1558 cm -1 [9,12].…”

The Application of Embelin for Cancer Prevention and Therapy

“…Encapsulation of copper (II) complexes with two ligands of embelin was catalytically active and greatly increased the oxygen binding ability of the metal ion. This finding has far reaching consequences in the applications of gas purification [ 117 ]. In another recent report, new derivatives of embelin that have aromatic groups linked to the benzoquinone core via the Suzuki–Miyaura reaction were synthesized and tested for its XIAP inhibitory activity in cancer cells [ 118 ].…”