Metallomicellar Catalysis: Hydrolysis of Pnpp by Crowned Schiff Base Cobalt(Ii) Complexes in Micellar Solution

Abstract

It has been reported that three aza crowned Schiff cobalt(II) complexes have been synthesised and characterised, and that the metallomicelles, made up of the three cobalt(II) complexes and surfactants(LSS, Brij35, CTAB) as mimic hydrolytic metalloenzyme, were used in the catalytic hydrolysis of carboxylic ester (PNPP) over a pH range of 7.0 - 8.2. The results revealed that the metallomicelles made up of the three cobalt(II) complexes and the surfactants are both efficient for catalysing PNPP hydrolysis with about three orders of magnitude in rate acceleration compared with the background rate of PNPP spontaneous hydrolysis. The effect of different surfactant micelles on the catalytic hydrolysis of PNPP in the metallomicelles follows the order: LSS > Brij35 > CTAB. The results showed that using the aza crowned Schiff base cobalt(II) complexes and their metallomicelles as the hydrolase mimics exhibit good catalytic activity and similar catalytic character to natural enzyme.