Catalytic mechanism of Cu(p-OTs)2/ethanolamine as mimetic enzyme
(State Key Laboratory of Optoelectronic Materials and Technologies,
School of Physics and Engineering, Zhongshan University, Guangzhou 510275, China)
School of Physics and Engineering, Zhongshan University, Guangzhou 510275, China)
Abstract: The electrochemical behaviors of various copper salts complexes coordinated with equal molar ethanolamine were studied, and those of Cu(p-OTs)2 and Cu(p-OTs)2/ethanolamine(1∶1) complex in CH3OH or DMF were characterized. The results show that the reduction of Cu(Ⅱ) in Cu(p-OTs)2 is via one two-electron step mechanism both in CH3OH and DMF. The reduction mechanism transforms to two one-electron steps in the case of Cu(p-OTs)2/ethanolamine(1∶1) in DMF. However, it does not change in CH3OH. All the Cu(Ⅱ)/ethanolamine(1∶1) with the electrochemical reactions are through two one-electron steps, and can act as mimetic enzyme to oxidize 1,1′-bi-2-naphthol. The Cu(Ⅱ)/ethanolamine(1∶1) with electrochemical reactions through one two-electron step could not act as mimetic enzyme. It is concluded that the transformation between centre Cu(Ⅱ) and Cu(Ⅰ) is the crucial condition for the catalytic activity of copper-amine complex.
Key words: copper p-toluenesulfonate; mimetic enzyme; 1,1′-bi-2-naphthol; electrochemistry