Synthesis and Proton-Coupled Electron-Transfer Reaction of Self-Assembled Monolayers of a Ruthenium(II) Complex Containing Tridentate 2,6-Bis(benzimidazol-2-yl)pyridine on a Gold Surface: Comparison of Acid/Base Chemistry with Bulk Solution Chemistry
Synthesis and Proton-Coupled Electron-Transfer Reaction of Self-Assembled Monolayers of a Ruthenium(II) Complex Containing Tridentate 2,6-Bis(benzimidazol-2-yl)pyridine on a Gold Surface: Comparison of Acid/Base Chemistry with Bulk Solution Chemistry
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DOI：
10.1021/ic990934s
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发表时间：
2000-09
影响因子：
4.6
通讯作者：
Masa-aki Haga;‡. H. Hong;Y. Shiozawa;Y. Kawata;H. Monjushiro;and Tsuyoshi Fukuo;R. Arakawa
中科院分区：
文献类型：
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作者：
Masa-aki Haga;‡. H. Hong;Y. Shiozawa;Y. Kawata;H. Monjushiro;and Tsuyoshi Fukuo;R. Arakawa
采用MALDI-TOF质谱、XPS和循环伏安等方法研究了二硫键修饰的Ru（bimpyH 2）配合物在多晶金电极（bimpyH 2 = bis（benzimidazole-2-yl）pyridine）上的自组装和电化学性质.在0.1 M HClO 4水溶液中，Ru（III/II）在+0.66 V vsSCE处发生准可逆氧化. Ru（III/II）对的循环伏安图的形状强烈依赖于表面覆盖度，并且当Ru纯单分子膜被辛烷磺酸稀释时接近理想的伏安图。钌配合物与正辛烷磺酸混合单分子膜的氧化电位与溶液pH呈线性关系，表明在金表面发生了质子耦合的氧化反应。根据E1/2−pH曲线，在金表面上Ru混合单层的pKa值为Ru（II）态的pKa 1 = 6.0和pKa 2 = 7.8，Ru（III）态的pKa 1 = 1.5和pKa 2 = 3.4。Ru的pKa值...
The self-assembly and electrochemical properties of a novel Ru(bimpyH2) complex functionalized by disulfide on a polycrystalline gold electrode (bimpyH2 = bis(benzimidazol-2-yl)pyridine) were characterized by means of MALDI-TOF mass spectrometry, XPS, and cyclic voltammetry. The Ru complex monolayers exhibit a quasi-reversible Ru(III/II) oxidation at +0.66 V vs SCE in 0.1 M HClO4 aqueous solution. The shape of the cyclic voltammograms for Ru(III/II) couple is strongly dependent on the surface coverage, and is close to the ideal voltammogram when the Ru neat monolayers are diluted by octanethiol. The oxidation potential of the Ru complex mixed monolayers with octanethiol shows a linear dependence on solution pH, indicating that the proton-coupled oxidative reactions occurred on the gold surface. The pKa values for the Ru mixed monolayers on the gold surface were obtained as pKa1 = 6.0 and pKa2 = 7.8 for the Ru(II) state and ∼1.5 and 3.4 for the Ru(III) state from the E1/2−pH plots. The pKa values of the Ru...