Kinetic and Mechanistic Investigations of the Catalysed Hydrolysis of Bis(p-Nitrophenyl) Phosphate by a Macrocyclic Neodymium(III) Complex

Abstract

The macrocyclic ligand 5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclo-tetradecane (L) was synthesised and characterised. The kinetics of hydrolysis of bis( p-nitrophenyl) phosphate (BNPP) in a catalytic system comprising the macrocyclic ligand and neodymium(III) was investigated. The analysis of specific absorption spectra of the hydrolytic reaction system indicated that key intermediates containing BNPP and the Nd(III) complex are formed in the reaction. The mechanism proposed for the catalytic hydrolysis proposed is based on the analytical results of the specific absorption spectrum, and the corresponding kinetic constants are calculated. The results showed that the Nd(III) complex as a mimic hydrolase exhibits good catalytic activity, i.e. similar to that of the natural enzyme.