Metal-chelator polymers as reactive adsorbents for organophosphate hydrolysis

We describe the synthesis and hydrolytic properties of three monomeric Cu(II)-1,4,7-triazacyclononane chelators, containing one to three polymerizable N-vinylbenzyl substituents, and their insoluble polymerized forms. The rates of hydrolysis of methyl parathion (MeP) and bis-(4-nitrophenyl)phosphate (BNPP), expressed as their apparent Michaelis-Menten kinetic constants, were determined. The reported phosphodiester and phosphotriester catalytic rates are among the highest reported for insoluble polymers, with apparent catalytic constants of 1.0 X 10(-2) and 5.5 X 10(-4) s(-1) for MeP and BNPP, respectively. Unusual substrate inhibition was also observed at high substrate concentrations for the three polymers that were cross-linked using trimethylolpropane trimethacrylate (TRIM), whereas polymers formed from the pure monomers or from a mixture of monomeric and TRIM polymerizations did not exhibit substrate inhibition at the same concentrations. (C) 2003 Published by Elsevier Science B.V.