| Popis: |
The sol–gel method was used for the synthesis of a PEG–silica hybrid. In order to introduce PEG into the cavities of silica gel, first, the bis(3-trimethoxysilylpropyl)-polyethylene glycol precursor was synthesized by the reaction of 3-chloropropyltrimethoxysilane with alkoxides formed on the PEG terminals. The organic–inorganic hybrid silica was then synthesized by hydrolysis and polycondensation of the precursor under mild acidic conditions. The characteristics results of FT–IR, XRD and TGA confirmed the coexistence of silica and PEG networks. The catalytic ability of this heterogeneous catalyst to the regioselective ring opening of epoxides by azide and cyanide anions in H 2 O was also investigated. |
