Macrocyclic Zn(II) Complexes: Synthesis, Structure and Hydrolysis of p-Nitrophenyl Acetate (pNPA)

S.K. Pandey, M.L. Sharma, O.P. Pandey, S.K. Sengupta
2015 Journal of Institute of Science and Technology  
<p>A new series of Zn(II) macrocyclic complexes has been synthesized by the reaction of Schiff bases (derived from dihydrazides and benzil/phthalaldehyde) in the presence of zinc(II) acetate dihydrate in ethanol. The complexes have been characterized by means of elemental and spectral (IR, 1H and 13C NMR) and SEM analysis. The kinetic studies were done to study the catalytic properties of these complexes towards the hydrolysis of p-nitrophenylacetate (pNPA) at 25°C in aqueous dimethylsulphoxide
more » ... dimethylsulphoxide using phosphate buffer (pH = 7.0–8.5). During the reaction, absorbance of p-nitrophenolate increases with increase in time (i.e., increase of p-nitrophenolate concentration) which give information about the reaction progress i.e., ester hydrolysis. On the basis of these results, a plausible mechanism for the hydrolysis of pNPA is proposed. It is observed that coordinated water molecule might be serving as a good nucleophile that effectively catalyzes pNPA hydrolysis. Therefore, this type of complexes can be used as hydrolytic model enzymes.</p><p>Journal of Institute of Science and Technology, 2015, <strong>20(2): </strong>42-48</p>
doi:10.3126/jist.v20i2.13947 fatcat:c2zquisowbezdh4nna5mskftqm