Study of Activity and Catalytic Properties of Group 13 Cheate Compounds for Dealkylation or Organophosphates

Organophosphate esters are active components of chemical warfare agents like VX gas and Sarin and pesticides such as chloropyrifos and paraoxons. The cleavage of the P.O.C linkage in these molecules provides a first step for their destruction. In the proposed project various boron and aluminum chelate compounds will be examined as potential catalytsts for the cleavage of the oxygen-carbon bond in organic phosphates of the type (RO)3P(O). Both neutral compounds, L(MXn)2(L=Schiffbase ligand, e.g., Salen, M=B or AI, X = Br or Cl, n =1 or 2), and cations, [LM(base)2r~- (L=Schiffbase ligand, M=B or AI, base= H2O, MeOH, THF, and X= halide, OTf, OTs, BP14-),will be explored. The work is based upon the recent discovery that specifically designed boron chelate compounds cause the cleavage of the carbon-oxygen bond in a wide variety of phsophates. This discovery is now a patent submission (US Provisional Patent Application S.N. 60/445,985) entitled: 'Catalytic Cleavage of Phosphate Ester Bonds by Boron Chelates'. Subsequent to the patent submission it was found that the oxygen-carbon bond in the widespread water contaminant, methyl(tert)- butylether (MTBE) could also be cleaved with the boron compounds. Thus, toxic or problematic molecules containing either a P-O-C or a C-O-C linkage can be destroyed with the boron chelates. The proposed research will focus on defining the conditions and understanding the mechanism of the catalytic reaction in order to know how to apply the technology to realworld applications. In particular, it will be important to determine if chelated aluminum compounds can be effective. Many of these compounds are known, and they have exceptional air and moistue stability. The outcome of the proposed work would potentially be to establish two classes of chelates, boron and aluminum, for use in the catalytic cleavage of a wide variety of molecules containing either P-O-C or C-O-C bonds. Thus, it may be possible to tailor a specific catalyst to target a specific molecule for destruction.