Catalytic hydrolysis of phosphate esters by metallocomplexes of 1,10-phenanthroline derivatives in micellar solution

✍ Scribed by John G. J. Weijnen; Johan F. J. Engbersen

• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 708 KB
• Volume: 112
• Category: Article
• ISSN: 0165-0513
• DOI: 10.1002/recl.19931120608

✦ Synopsis

Abstract

Divalent metal‐ion complexes of 2,9‐bis[(methyldodecylamino)methyl]‐1,10‐phenanthroline (C~12~PhenM^II^) in neutral Brij 35 micelles catalyse the hydrolysis of various phosphate triesters, diesters and monoesters. The catalytic activity of C~12~PhenM^II^ has been compared with that of the metal‐ion complexes of its water‐soluble counterpart 2,9‐bis[(dimethyl‐amino)methyl]‐1,10‐phenanthroline (C~1~PhenM^II^). Saturation kinetics provide evidence for preliminary formation of ligand‐M^II^‐phosphate ester complexes, which decay to products. The hydrolysis of diphenyl 4‐nitrophenyl phosphate (1b) coordinated to C~12~PhenZn^II^ proceeds 8700 times faster than the hydrolysis of 1b in the absence of metallocatalyst. Kinetic studies indicate that phosphate triesters containing a metal‐ion‐binding site in close proximity to the phosphoryl bond, i.e., diphenyl 5‐nitro‐2‐pyridyl phosphate (2b) and diphenyl 5‐nitro‐8‐quinolyl phosphate (3), are hydrolysed by the same mechanism as 1b.