Metal–chelator polymers as reactive adsorbents for organophosphate hydrolysis

Abstract

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 1.0×10 −2 and 5.5×10 −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.