Abstract
Fe3+ complexes of pyridine-containing copolymers were found to be efficient and selective catalysts toward phosphodiester hydrolysis and show significant activity toward oxidative DNA cleavage. The catalysis toward bis(p-nitrophenyl)phosphate (BNPP) hydrolysis exhibits enzyme-like pre-equilibrium kinetics with maximum activities in the range of ca. pH 6-8 and a first-order catalytic proficiency (k(cat)/k(o)) of 4.2 X 10(7)-fold at the acidic pH value of 5.3 (i.e., pK(a) of the coordinated nucleophilic water) and 25 degrees C, entitling this Fe3+ copolymer an acid phosphodiester catalyst, This catalyst also shows significant selectivity toward BNPP hydrolysis relative to the hydrolyses of p-nitrophenyl phenylphosphonate and p-nitrophenylphosphate monoester, with a ratio of 4250:16:1 in terms of their first-order catalytic proficiencies at pH 8.0 and 25 degrees C. Fe3+ complexes of a few pyridin e-containing copolymers show different hydrolytic activities, which points a direction for rational design of catalytic metallopolymers. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)