INOR 833 |
| The conversion of methanol to hydrocarbons catalyzed by zinc or indium iodide at 200 °C has been shown to give surprisingly high selectivity (up to 20% based on carbon) for one highly-branched C7 alkane, 2,2,3-trimethylbutane (triptane). As part of our ongoing studies into the mechanism of this reaction we recently discovered that the addition of small amounts of phosphorus additives such as H3PO2 and H3PO3 can result in a twofold increase in the yield of triptane in reactions catalyzed by ZnI2. The proposed mechanism involves the effective donation of a hydride from the phosphorus additive to carbocation intermediates, which is an unusual mode of reactivity for P-H compounds. In contrast, phosphorus additives do not increase the yield of triptane in reactions catalyzed by InI3. The differences between zinc and indium catalyzed reactions, general reasons for the selective formation of triptane and the specific role of phosphorus additives will all be discussed. |
|
Inorganic Catalysts
8:30 AM-12:10 PM, Wednesday, August 22, 2007 BCEC -- 209, Oral
Division of Inorganic Chemistry |