摘要
合成了两种大环过渡金属配合物NiR和CuR(R表示高氯酸-5,7,7,12,14,14-六甲基-1,4,8,11-四氮杂环十四烷),将NiR和CuR分别与表面活性剂正月桂酸肌氨酸组成金属胶束,并以其为模拟水解金属酶用于催化对硝基苯酚吡啶甲酸酯(PNPP)水解.特征光谱分析表明,在催化PNPP水解过程中形成了由Ni(Ⅱ)或Cu(Ⅱ)配合物与PNPP组成的中间物种,并由此提出了催化PNPP水解的机理,建立了用于计算动力学常数的动力学模型.
Two transition metal ion macrocyclic complexes, NiR and CuR （R： 5,7,7,12,14,14-hexamethyl- 1, 4,8, 11-tetraaza-cyclotetradecane perchloric acid）, were synthesized and characterized. Metallomicelles made up of nickel（ Ⅱ ） and copper（ Ⅱ ） complexes with surfactant n-lauroyl sarcosinate （LSS） were used as a mimetic hydrolytic metalloenzyme for catalytic hydrolysis of p-nitrophenyl picolinate （PNPP）. The specific absorption spectra of the hydrolytic reaction systems indicated that the key intermediates made up of PNPP and Ni（ Ⅱ ） or Cu （ Ⅱ ） complexe were formed during the reaction process. Based on the specific absorption spectra, the mechanism of PNPP catalytic hydrolysis was proposed, and a kinetic mathematical mode was established. The results showed that the two metallomicelles exhibit high catalytic activity for the hydrolysis of PNPP. The catalytic hydrolysis of PNPP is an intramolecular nucleophilic substitution reaction, so the rate of the catalytic reaction is higher than that of spontaneous hydrolysis. The catalytic mechanism proposed is supported by the results of spectral analysis and the kinetic calculation. The structure of NiR and CuR is similar so that the difference of catalytic activity between the two metallomicelles is less.
出处
《催化学报》
SCIE
EI
CAS
CSCD
北大核心
2007年第4期383-388,共6页
基金
国家自然科学基金(50572121)
重庆市自然科学基金(2006BB7389).
关键词
金属胶束
模拟水解酶
羧酸酯
水解
机理
动力学
metallomicelle
mimic hydrolase
carboxylic ester
hydrolysis
mechanism
kinetics
