Post-modification of mesoporous silica with different nitrogenous bases for immobilization of manganese porphyrin: synthesis, characterization and catalytic activity

In this study, SBA15 functionalized by imidazole or pyridine as nitrogenous bases, the novel recoverable catalysts prepared by coordinative anchoring of manganese(III) complex of meso -tetraphenyl porphyrin (MnTPP(OAc)) on the functionalized SBA15 and the hybrid catalysts fully characterized by standard methods. The catalytic efficiency of the supported catalysts was evaluated for the oxidation of sulfides and alkenes with urea hydrogen peroxide and tetrabutylammonium peroxymonosulfate as oxidant. The co-catalyst activity of imidazole and pyridine for the oxidation reactions in the presence of MnTPP(OAc) compared with each other in both homogeneous and heterogeneous systems. Our results demonstrated that the product yields of the oxidation reaction reflect the co-catalytic activities of the nitrogenous donor in the homogeneous systems, but not in heterogeneous one. The attached nitrogen bases showed a relatively similar effect on the catalytic activity of Mn-porphyrin in the oxidation reactions. The main effect of the tethered co-catalyst was observed on the reusability of the supported catalysts. Graphical abstract