various co-polymers of mba-poly(n-vinyl-2-pyrrolidone) macromolecular coordination complex as a novel and recyclable lewis acid catalyst: synthesis, characterization, and performance towards well-know organic reaction

A novel macromolecular-metal coordination complex, mba-cross-linked pnvp/lewis acid material was fabricated by ferric chloride/titanium chloride/zirconium chloride onto the porous cross-linked poly(n-vinyl-2-pyrrolidone) carrier beads as a macromolecular ligand or carrier which was prepared by suspension free-radical copolymerization of n-vinyl-2-pyrrolidone (nvp) and various percent of n, n’-methylene bis-acrylamide (mba) as a crosslinking agent in water. the obtained mba-cross-linked pnvp/lewis acid w:as char:acterized by uv/vis and ft-ir spectroscopies, tga, fe-sem, edx, and icp techniques. comparison to select the optimum percentage of a crosslinking agent as the purpose of this study and the amount of lewis acids loading has been done by a edx , icp, and mohr titration method. this heterogenized version of ferric chloride/titanium chloride/zirconium chloride is a convenient and safe alternative to highly water intolerant proportion of homogeneous the same lewis acid. the catalytic performance of pnvp/(fecl3, ticl4, zrcl4) as an efficient and recyclable polymeric lewis acid catalyst was appropriately probed in the regio-and stereoselective nucleophilic ring-opening of various epoxides with various alcohols in excellent yields without generating any waste and the biginelli reaction. the experimental outcome revealed that using the copolymer beads as carriers with a high percentage of crosslinking and the high mesh size leads had an adverse effect on the reaction rate, the optimum crosslinking agent is 4% of mba with 4.38 mmol/gr, 5.09 mmol/gr and 0.53 mmol/gr for fecl3, ticl4, zrcl4, respectively. also data shows that heterogeneous catalyst is very active and could be easily recovered, and reused at least 6 times without appreciable loss of activity indicating its stability under experimental conditions.