ISSN:
0887-624X
Schlagwort(e):
Chemistry
;
Polymer and Materials Science
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
Notizen:
Catalysis of the solvolysis of organophosphorus esters by polymers of aliphatic amines, imidazole, pyridine, 2,2′-bipyridine, and their copper(II) complexes was studied using diisopropyl fluorophosphate (DEP) as a model substrate. The polymeric catalysts were synthesized either by (1) derivation of available polymers, including polyethylenimine, polyvinyl amine, polyvinyl alcohol, polystyrene, and poly-4-vinylpyridine or (2) by polymerization of functionalized monomers such as 4(5)-vinylimidazole and 4-vinyl-4′-methyl-2,2′-bipyridine. Polymer hydrophilicity was controlled by partial quaternization of amine groups with different alkyl halides. The greatest catalytic activity was exhibited by copper(II) complexes of polymers containing the 2,2′-bipyridine group. At pH 7.6 and 3.7 × 10-3M, the most active of these catalysts reduced the half-life of DFP from 800 to 9 min. The rate was largely independent of the pH in the range 6.5-8.5 but was limited by the aqueous solubility of the catalyst. Heterogeneous catalysis by some polymers was observed but was less effective. A Lineweaver-Burk plot of V0-1 versus [DFP]-1 for a soluble polymeric 2,2′-bipyridine-copper(II) catalyst was linear. There was no correlation between catalysis of solvolysis of DFP and the carboxylic ester, p-nitrophenyl acetate.
Zusätzliches Material:
3 Ill.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/pola.1990.080280405
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