HYDROLYSIS OF P-NITROPHENYL PICOLINATE CATALYZED BY COPPER(II ) COMPLEXES OF LONG ALKYL-PYRIDINES WITH HYDROXYL GROUPS IN MICELLAR SOLUTION

ABSTRACT

A ternary complex kinetic model for metallomicellar catalysis has been proposed in this paper. Hydrolysis of PNPP influenced by Co-micelles of long alkyl-pHridines with hydroxyl groups and CTAB was investigated in aqueous buffers of pH ranging from 5. 0 to 7. 0 at 30°C at present of Cu²⁺. The kinetic and the thermodynamic parameters (K_n', K_m', K_T) were obtained by the kinetic analyses,moreover,the rate constant K_n in metallomi-cellar phase was obtained. The pK_ϵ s of the hydroxyl groups of these complexes were determined to be 5. 62,5. 53,5. 34,5. 32,respectively by analyses of pH-rate profiles. The results indicate that pyridine ligands exhibit a great catalysis on the hydrolysis of PNPP,which increases with increasing the hydrocarbon chain length.

Keywords:

• Metallomicelle
• Hydrolysis of PNPP
• Catalysis
• Pyridine ligands