An Anionic Surfactant Metallomicelle: Catalytic Activity and Mechanism for the Catalytic Hydrolysis of a Phosphate Ester

Abstract

An aza-crown ether ligand was synthesised and characterised. The chemical composition of the binary complex containing cerium(III) and the ligand was determined by fluorescence spectroscopy. A new metallomicellar system comprising the cerium(III) complex of the ligand and an anionic micelle (n-lauroylsarcosine) was used as catalyst in the hydrolysis of bis(4-nitrophenyl) phosphate ester (BNPP). The catalytic rate of BNPP hydrolysis and the local concentration effect of the micelle were measured kinetically using UV-Vis spectrophotometry. The results indicated, that compared with a cationic metallomicelle system made from the aza-crown ether, lanthanum(III) ion and CTAB cationic surfactant in our previous report, the anionic metallomicelle exhibited a six-fold higher catalytic activity in BNPP hydrolysis at neutral pH and the same other conditions, thus the micelle based on LSS provides a more effective catalytic environment for reaction. A reaction mechanism has been proposed.

Cyclononanes: The extensive chemistry of fundamentally simple ligands

“…In many respects this has come to fruition. The extensive studies of the models of the NO-inactivated iron containing nitrile hydratase (NHases) based on the [9]aneN 2 S ligand [71,[150][151][152][153][154], and the phosphoesterase models based on [9]aneN 2 O [257][258][259] are examples of applications in modelling bio-sites; the [9]aneN 2 S ligand has been employed as the basis for fluorescent…”