Preparation and catalytic properties of RuSalen-functionalized periodic mesoporous silicas

• Chloromethylation was performed on phenylene sites in the framework of PMOs.
• Amination of PMOs was achieved via reacting –C4H3CH2Cl– with piperazine.
• RuSalen could be covalently attached on aminated PMOs.
• RuSalen on aminated PMOs showed higher activity in cyclohexene oxidation with H2O2.
• RuSalen on aminated PMOs were more stable than that on aminated SBA-15.

A new approach was employed to prepare metal complex-functionalized periodic mesoporous silica. This approach mainly involves the following three steps, that is, chloromethylation of –C6H4– sites in the framework of PMOs into active –C6H3CH2Cl–, amination of PMOs via reacting –C6H3CH2Cl– with piperazine and covalent attachment of RuSalen by refluxing the aminated PMOs in RuSalen ethanol solution. The obtained hybrid material was characterized with XRD, N2 sorption, FTIR, diffuse reflectance UV–vis spectroscopy, TEM and 13C MAS NMR techniques. It shows higher activity and stability in the oxidation of cyclohexene with H2O2 than the corresponding RuSalen functionalized SBA-15 prepared by the similar method except that the introduction of active –C3H6Cl was achieved by grafting 3-chloropropyltriethoxysilane on SBA-15.

Figure optionsDownload as PowerPoint slide