Comparative studies on hydrolysis of bis(p-nitrophenyl) phosphate catalyzed by short- and long-alkyl-multiamine metallomicelles

Four short- and long-alkyl-multiamine ligands L1–L4 have been synthesized and characterized. The catalytic efficiency of complex CuL1 and functional metallomicelles CuL2–CuL4 were comparatively investigated for the hydrolysis of bis(p-nitrophenyl) phosphate (BNPP) in buffered solution at 30 °C. The ternary kinetic model for metallomicellar catalysis was suggested to analyze the experimental data. The kinetic and thermodynamic parameters k ′ N , KT and pKa were obtained. The results indicated that the complexes with 1:1 ratio of ligands L2–L4 to copper(II) ion were the kinetic active catalysts, and the deprotonized Cu(II) complex formed by activated water molecule was the real active species for BNPP catalytic hydrolysis. The real rate constant of the reaction catalyzed by CuL1–CuL4 was 4.00 × 10−6, 7.44 × 10−5, 1.42 × 10−4 and 4.10 × 10−4 s−1, respectively. The effects of ligand and microenvironment on the hydrolytic reaction of BNPP have been discussed in detail.