Polymer-supported Schiff base complexes in oxidation reactions

Synthesis and Structural Studies of Nickel Complex Supported by-ONNO-Tetra Dentate Schiff-Base Ligand: Efficient Catalysts for Oxidation of Phenol

“…The supported catalysts are easily recovered without any substantial loss in their catalytic activity [1][2] but homogeneous catalysts are not recovered easily. The Schiff base complexes of transition metal ions shown high catalytic activities in various chemical reactions such as epoxidation of olefins, [3] oxidation, [4][5] and polymerization of ethylene, [6][7] but polymer-supported metal complexes showed high catalytic activity [4,5,[8][9][10], in comparison to homogeneous catalysts. The manganese(II) salen complexes anchored on tailor-made polymers were more enantioselective without any mass transfer limitation for alkenes on polymer supports.…”

“…[17] The metal complexes on solid supports are immobilized either physically or by forming a covalent bond between metal complexes and supports. [8] But the recovery of physically linked catalysts has been found to be low in comparison to covalently bound catalysts due to the leaching of catalysts. The oxidation of phenol using unsupported Schiff base complexes of metal ions is reported, [18] but the oxidation of phenol using polymer-supported transition metal complexes was found to be high [19] in the presence of tert-butyl hydroperoxide (t-BHP).…”

“…The manganese(II) salen complexes anchored on tailor-made polymers were more enantioselective without any mass transfer limitation for alkenes on polymer supports. [11] The transition metal complexes were also anchored on other supports, [12][13][14][15] and have been used in selective oxidation of phenols but oxidation of phenol using metal salen complexes on polymer supports found to be more efficient and selective in comparison to homogeneous systems, as the polymeric supports provided better control on efficiency of catalysts [8] due to microenvironment provided by polymer chains for the substrates in comparison to zeolites [16] and silica. [17] The metal complexes on solid supports are immobilized either physically or by forming a covalent bond between metal complexes and supports.…”

Intercalation of Schiff Base Ligands with Copper (ІІ) and Nickel (ІІ) Cation-exchange Montmorillonite (MMT) Nanoclay

“…Schiff base metal complexes have found their applications as catalysts in a wide range of reactions, such as polymerisation, epoxidation of olefins, ring-opening polymerisation, carbonylation reactions and oxidation reactions. [1][2][3][4][5] Tridentate oxygen-nitrogen-nitrogen (ONN) Schiff base ligands containing anionic amines (RNH) were used to prepare metal Schiff base complexes, 6,7 while tridentate metal Schiff base complexes were used as catalysts in Heck 8 and Suzuki-Miyaura cross coupling reactions. 9 Among the different types of clay, montmorillonite (MMT) has been extensively used for modification due to its excellent properties, such as high cation exchange capacity, swelling behaviour, adsorption properties and its large surface area.…”

Syntheses, spectroscopic and magnetic properties of polystyrene-anchored coordination compounds of thiazolidinone

“…Heterogenization or immobilization of active metal complexes on polymeric supports has evolved as a promising strategy for combining the advantages of homogeneous and heterogeneous catalysts due to their easy isolation from the products by filtration and the possibility of recycling them or continuous operation in a reactor [2]. A structural study of polymer-anchored compounds seems useful in view of their numerous applications in analytical chemistry [3], metal ion removal [4], immobilization of enzymes [5], antimicrobial activities [6], as catalysts [7][8], as solid supports [9], as substrate carriers [10] and a s ion-exchanger [11], etc.…”