Metallomicellar Catalytic Hydrolysis of Bis(4‐nitrophenyl) Phosphate by Cu^IINi^II Heterodinuclear Complexes in Brij35 Micellar Solution

Abstract

The hydrolysis of bis(4‐nitrophenyl) phosphate (BNPP) catalyzed by metallomicelles formed from three asymmetry oxamido‐bridged Cu(II)Ni(II) heterodinuclear complexes containing different diamine groups and Brij35 micelle has been investigated kinetically in the pH range of 6.0–10.0 at 25°C. The results indicate that these complexes show relative high reactivity in Brij35 micellar solutions. Complex III exhibited a more effective catalytic function than complex I and complex II for the hydrolysis of BNPP, which was attributed to the different structure of the diamine group in the complex. The apparent rate constants (k _obsd ) of BNPP hydrolysis increased with the increasing pH values of reaction media and then reached saturation near pH 9.0. The kinetic and thermodynamic parameters (K and k) were obtained, and the studies show that the hydrolysis of BNPP involves a bifunctional mechanism and is an intramolecular nucleophilic reaction. In the reaction systems, the kinetically active species has been determined to be the aquo‐hydroxo form of the complex CuNi(H₂O)OH in Brij35 micellar solution.

Keywords:

• Hydrolysis of BNPP
• metallomicellar catalysis
• heterodinuclear complex
• catalytic mechanism

Acknowledgment

This work was supported by the National Natural Science Foundation of China (Grant Nos: 20173038 and 20107004).