Preparation and catalytic properties of RuSalen-functionalized periodic mesoporous silicas

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, N-2 sorption, FTIR, diffuse reflectance UV-vis spectroscopy, TEM and C-13 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-chloropropyltriethoxy-silane on SBA-15. (C) 2014 Elsevier Inc. All rights reserved.