INOR 827 |
| Organophosphate esters are active components of chemical warfare agents and pesticides. The cleavage of the P-O-C linkage in these molecules provides a method for their destruction. The presentation will describe how binuclear boron halide compounds of the type L[BX2]2 (L= Salen(tBu) ligands, X= Cl, Br) can dealkylate a wide range of organophosphate compounds, including actual nerve agents, with high conversion at room temperature(1). The reactions are catalytic in the presence of excess BBr3 and are thought to proceed through the formation of a phosphate coordinated boron cation. More recently it has been found that the compounds LBX (L= Sal ligands, X=Br, Cl) and Salen(tBu)AlBr (2) can also dealkylate organophosphates. Structural characterization of the dealkylation intermediates reveals that they can be monomeric or dimeric (3). A method for the use of the compounds in gas mask filters will be described. (1) T. S. Keizer, L. J. De Pue, S. Parkin and D. A. Atwood, "Catalytic Dealkylation of Phosphates with Binuclear Boron Compounds," J. Am. Chem. Soc., 124, 1864-1865 (2002). (2) A. Mitra, L. J. DePue, S. Parkin and D. A. Atwood, "Five-Coordinate Aluminum Bromides: Synthesis, Structure, Cation Formation, and Cleavage of Phosphate Ester Bonds," J. Am. Chem. Soc., 128, 1147-1153 (2006). (3) A. Mitra, S. Parkin and D. A. Atwood, "Aluminum Phosphinate and Phosphates of Salen Ligands," Inorg. Chem., 45, 3970-3975 (2006).
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Inorganic Catalysts
8:30 AM-12:10 PM, Wednesday, August 22, 2007 BCEC -- 209, Oral
Division of Inorganic Chemistry |