Highly Selective Organic Synthesis within Organized Nanopores as a Photocatalytic Reactor

点击翻译按钮获取中文摘要

This research work aims at the design and development of selective organic transformation processes using organized nanopores as the photocatalytic reactor.We have found that Ti-containing porous silica (titanosilicate) catalysts promote a selective conversion of molecules having a size close to the catalyst pores. This catalytic property can be applied for selective transformation of molecules having a size close to the catalyst pores to molecules having a smaller size. We also found that mesoporous titanium dioxide catalyzes a selective conversion of molecules adsorbed well on the catalyst surface. This catalytic property can be applied for selective transformation of well-adsorbed molecule to less-adsorbed molecule : for example, a direct hydroxylation of benzene to phenol was successfully promoted with >80% selectivity. We also found that a zeolite containing an organic photosensitizer within the supercage, when activated by a visible light with molecular oxygen, promote a selectiv … More e transformation of olefins to carbonyl compounds with >99% selectivity.We also aimed at the selective organic transformation through the precise designing of the photocatalytic active species. We found that Ti-containing mesoporous silica (meso-titanosilicate), when activated by UV irradiation with molecular oxygen, catalyzes selective photoepoxidation of olefins with very high selectivity. We also found that Cr-containing silica, when activated by visible light with molecular oxygen, catalyzes selective transformation of cyclohexane to cyclohexanone and partial oxidation of olefins. In addition, we synthesized new V-containing mesoporous silica, which contains V-oxide species "confined" within the silica layer. The V-oxide species are stable against water and show high photocatalytic activity.We also aimed at the selective organic transformation with organic polymer catalysts. We synthesized an amphiphilic dendrimer photocatalyst containing a photosensitizing core within the hydrophobic environment surrounded by hydrophilic dendrons. The photocatalyst efficiently catalyzes a photooxygenation of sulfides to sulfoxides. We also synthesized a random polymer photocatalyst comprised of an organic photosensitizing molecule and poly-N-isopropylacrylamide. We found that the catalyst shows unprecedented temperature-dependent photocatalytic activity for oxygenation in water. Less