Photosensitizers covalently anchored to the silica surface: Enhanced efficiency of heterogeneous photodechlorination of chlorinated aromatics.

A naphthol sensitizer is covalently anchored on silica. The so obtained heterogeneous as well as the corresponding homogeneous photosensitizer, under anionic form, have been tested in the reductive dechlorination of chloroaromatics. In these photoinduced electron transfer (PET) sensitized reactions, interactions between the sensitizer and the surface are shown to enhance their reactivity. The grafted silica is shown to work in the dechlorination of a tetrachlorobiphenyl acid sunlight reactions have been performed.