Hydrolysis of phosphate diester catalysed by transition metal complexes of a salicylaldimine Schiff base bearing dibenzo-18-crown-6

Abstract

A new crowned Schiff base ligand and its cobalt(II) and manganese(III) complexes were synthesised and characterised. These complexes were used to catalyse the hydrolysis of bis(4-nitrophenyl) phosphate (BNPP) in order to mimic the action of hydrolytic metalloenzymes. The kinetics and the mechanism of the titled reactions were investigated. The change of the characteristic ultraviolet spectra of the reaction systems was also analysed. A kinetic mathematical model of BNPP cleavage catalysed by the complexes is proposed. The function of the crown ether ring and the effects of the reaction conditions on the catalytic hydrolysis of BNPP are discussed.

Synthesis and phosphatase activity of a Cobalt(II) phenanthroline complex

“…Here, in solution, metal coordinated water molecule plays the most significant role to facilitate hydrolytic cleavage Phosphoesterase mimics by cobalt(II) complexes are not extensively studied and a few comparative studies of phosphoester cleavage is available in recent literature. [40][41][42][43] Previous studies have suggested that the coordinated alcohol is deprotonated at higher pH or coordinated water molecule 44 below the same pH. Both the coordinated alcohol and water molecule act as effective nucleophiles.…”