Catalytic Hydrolysis of P-Nitrophenyl Picolinate by Triethanolamine Co(II) Complex-Based Metallomicelle

Abstract

The catalytic hydrolysis of p-nitrophenyl picolinate (PNPP) by triethanolamine Co(II) complex in the presence or in the absence of CTAB and Triton X-100 micelle was investigated. The results indicated that triethanolamine Co(II) complex promoted the hydrolysis of PNPP by the addition of the catalytic effect of triethanolamine and Co(II), however, in the presence of CTAB and Triton X-100 micelle, triethanolamine Co(II) complex exhibited a remarkably catalytic effect on the hydrolysis of PNPP, indicating the formation of the metallomicelle. According to the proposed ternary complex kinetic model for metallomicellar catalysis, the obtained thermodynamic and kinetic parameters explained well the mechanism of the catalytic hydrolysis of PNPP.

Keywords:

• Catalytic hydrolysis
• metallomicelle
• PNPP
• triethanolamine Co(II) complex

Acknowledgments

This work was supported by the Key Program of Sichuan Educational Department (07ZS005), Training Funds of Academic and Technological Leader of Sichuan Province, the Key Program of Leshan Science and Technology Bureau, and the National Natural Science Foundation of China (Grant: 20973087).

Notes

^a In 0.1 mol dm⁻³Tris–TrisH⁺ buffer (μ = 0.1 KNO₃). [CTAB] = 0.001 mol dm⁻³, [Triton X-100] = 1 × 10⁻⁴ mol dm⁻³, [TEA] = 1 × 10⁻³ mol dm⁻³, [Co²⁺] = 1 × 10⁻³ mol dm⁻³, [PNPP] = 5 × 10⁻⁵ mol.

^a [CTAB] = 1.00 × 10⁻³ mol dm⁻³; [Triton X-100] = 1.00 × 10⁻⁴ mol dm⁻³; [PNPP] = 5.00 × 10⁻⁵ mol dm⁻³; μ = 0.1 (KNO₃).

^a [CTAB] = 1.00 × 10⁻³ mol dm⁻³; [Triton X-100] = 1.00 × 10⁻⁴ mol dm⁻³; [PNPP] = 5.00 × 10⁻⁵ mol dm⁻³; μ = 0.1 (KNO₃).