ORGN 123 |
| Development of efficient and highly selective methods for photocatalytic organic synthesis is one of the biggest challenges in chemistry. Here we report that ultraviolet light activation of titanosilicate molecular sieves, a Ti-containing silicious zeolite, in water in the presence of molecular oxygen, catalyze a conversion of molecules having a size close to the pore of the catalysts but are inactive for molecules having much larger or smaller size. This unprecedented "size-screening" photocatalytic activity is triggered by a combination of water-induced shortened lifetime of active species (charge-transfer excited state of tetrahedrally coordinated titanium oxide) and restricted diffusion of a molecule inside the pore. We highlight here a successful application of this unusual photocatalytic activity to a selective transformation of molecules that is associated with a size reduction of molecules, so-labeled "molecular shave" transformation. |
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Asymmetric Reactions and Syntheses, Physical Organic Chemistry, Combinatorial Chemistry, Total Synthesis
8:00 PM-10:00 PM, Sunday, 26 March 2006 Georgia World Congress Center -- Ex. Hall B4, Poster
Division of Organic Chemistry |