Breton Tony, Bélanger Daniel
Département de Chimie, Université du Québec à Montréal, Case Postale 8888, Succursale Centre-Ville, Montréal, Québec, Canada.
Langmuir. 2008 Aug 19;24(16):8711-8. doi: 10.1021/la800578h. Epub 2008 Jul 25.
The electrochemically induced functionalization of glassy carbon electrode by aryl groups having an aliphatic amine group was achieved by reduction of in situ generated diazonium cations in aqueous media. The corresponding diazonium cations of 4-aminobenzylamine, 2-aminobenzylamine, 4-(2-aminoethyl)aniline, N-methyl-1,2-phenylenediamine, and N, N-dimethyl- p-phenylenediamine were generated in situ with sodium nitrite in aqueous HCl. The kinetics of electrochemical grafting were investigated with electrochemical impedance spectroscopy and electrochemical quartz crystal microbalance measurements (with carbon-coated quartz crystal), and the barrier properties of the grafted layers were evaluated by cyclic voltammetry in the presence of electroactive redox probes such as Fe(CN)6 3-/4- and Ru(NH 3)6 (3+). The grafting efficiency of aryl groups was found to depend on the nature of the amine (primary, secondary, and tertiary), the chain length of the alkyl substituent, and the substitution position on the aromatic ring. The nitrosation of the "aliphatic" amine, in the case of secondary and tertiary amines, was also evidenced by X-ray photoelectron spectroscopy.
通过在水介质中还原原位生成的重氮阳离子，实现了具有脂肪胺基的芳基对玻碳电极的电化学诱导功能化。在盐酸水溶液中，用亚硝酸钠原位生成4-氨基苄胺、2-氨基苄胺、4-(2-氨基乙基)苯胺、N-甲基-1,2-苯二胺和N,N-二甲基对苯二胺的相应重氮阳离子。用电化学阻抗谱和电化学石英晶体微天平测量（使用碳涂覆石英晶体）研究了电化学接枝的动力学，并在存在Fe(CN)6 3-/4-和Ru(NH 3)6 (3+)等电活性氧化还原探针的情况下，通过循环伏安法评估了接枝层的阻隔性能。发现芳基的接枝效率取决于胺的性质（伯胺、仲胺和叔胺）、烷基取代基的链长以及芳环上的取代位置。X射线光电子能谱也证明了仲胺和叔胺情况下“脂肪族”胺的亚硝化反应。
