Superiority of Activated Carbon versus MCM‐41 for the Immobilization of Molybdenum Dithiocarbamate Complex as Heterogeneous Epoxidation Catalyst

Abstract

Two heterogeneous catalysts were developed by covalent anchoring of molybdenum‐dithiocarbamate complex onto the mesoporous silica (MCM‐41) and activated carbon (AC). Characterization of the functionalized materials by various physicochemical techniques indicated that the molybdenum complex is grafted successfully on the surface of supports. Textural properties of the prepared catalysts proved that the surface properties of supports have been changed after grafting of molybdenum‐dithiocarbamate complex. These heterogeneous catalysts were utilized for the epoxidation of olefins with tert‐butyl hydroperoxide (TBHP) as oxidant, presenting high efficiency and facile recovery. These catalysts can be reused five times without apparent loss of their catalytic performance. Also, the effect of the nature of MCM‐41 and AC supports on the catalytic activity has been discussed based on their hydrophobic and hydrophilic character.

Immobilized Cu‐Schiff Base Complex on MCM‐41as Catalyst in the Synthesis of Benzimidazole Derivatives

“…MCM‐41 (hexagonal), MCM‐48 (cubic), MCM‐50 (lamellar) are the three members of M41S family with different mesophases [29] . Most of the researches were carried out by using mesoporous MCM‐41 as a support because of its tailorable textural properties and excellent thermal and mechanical stability among all other solid supports [30–33] . Bharathi et al.…”

“…[29] Most of the researches were carried out by using mesoporous MCM-41 as a support because of its tailorable textural properties and excellent thermal and mechanical stability among all other solid supports. [30][31][32][33] Bharathi et al synthesized a heterogeneous catalyst by immobilizing a Ni-Schiff base metal complex on MCM-41 for benzimidazole synthesis. [34] Niakanet al prepared MCM-41 supported Cu-schiff base metal complex for C (aryl)-N Ullmann reactions.…”

Preparation, Characterization and Application of Copper Schiff base Complex Supported on MCM‐41 as a Recyclable Catalyst for the Ullmann‐type N‐arylation Reaction

“…These materials have high surface areas, large ordered pores ranging, and rigid framework . The most extensively studied mesoporous silica materials is MCM‐41 with a hexagonally arranged uniform pore structure and high thermal stability, while other materials were thermally unstable or difficult to obtain . More importantly, the presence of a large number of free silanol groups on the surface of MCM‐41 provided the immobilization of suitable functional groups which can act as strong binding sites for metal complexes as valuable catalysts on its surface …”

“…[25][26][27][28] The most extensively studied mesoporous silica materials is MCM-41 with a hexagonally arranged uniform pore structure and high thermal stability, while other materials were thermally unstable or difficult to obtain. [29][30][31] More importantly, the presence of a large number of free silanol groups on the surface of MCM-41 provided the immobilization of suitable functional groups which can act as strong binding sites for metal complexes as valuable catalysts on its surface. [32] Although there are various reports in the literature about the use of copper complexes immobilized on mesoporous silica materials as catalysts in the N-arylation reaction, in most of them, the reactions were carried out in toxic organic solvents and at high temperatures.…”

Remarkable binuclear Schiff‐based complex catalyze the epoxidation of alkenes: effects of substituent group

“…Therefore, complexes possess high oxidation central metals are the most suitable and most popular catalysts in catalytic oxidation . Among them, molybdenum‐based complexes have attracted a lot of attention and show the highest catalytic activity and selectivity . Besides, molybdenum complexes offer significant advantages such as lower cost, environmental protection and commercialization.…”