Metal-promoted hydrolysis of bis(p-nitrophenyl)phosphate by trivalent manganese complexes with Schiff base ligands in Gemini micellar solution

Two crowned Schiff base manganese(III) complexes (MnL2Cl, L = L1, L2) were used to catalyze the hydrolysis of bis(p-nitrophenyl)phosphate (BNPP) in Gemini surfactants [bis(hexadecyldimethylammonium)hexane bromide (abbreviation 16-6-16, 2Br−)] solution. In comparison with the rate of BNPP spontaneous hydrolysis, a six orders of magnitude in rate enhancement was observed in Mn L 2 1 Cl /16-6-16 and Mn L 2 2 Cl /16-6-16 systems. Owing to the different structure, Mn L 2 2 Cl shows better activity than Mn L 2 1 Cl . Especially, the effects of three different micelles, i.e., 16-6-16 micelles, CTAB (hexadecyltrimethylammonium bromide) micelles, LSS (n-lauroooylsarcosine sodium) micelles, on the hydrolysis of BNPP catalyzed by Mn L 2 2 Cl were evaluated at pH7.50. Experimental observations clearly demonstrate that Gemini 16-6-16 micelle is the best one for BNPP hydrolysis among three kinds of micellar media.