Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue Madison, Wisconsin 53706, United States.
ACS Appl Mater Interfaces. 2011 Aug;3(8):3110-9. doi: 10.1021/am200615r. Epub 2011 Jul 29.
We demonstrate the use of "click" chemistry to form electrochemically and photoelectrochemically active molecular interfaces to SnO(2) nanoparticle thin films. By using photochemical grafting to link a short-chain alcohol to the surface followed by conversion to a surface azide group, we enable use of the Cu(I)-catalyzed azide-alkyne [3 + 2] cycloaddition (CuAAC) reaction, a form of "click" chemistry, on metal oxide surfaces. Results are shown with three model compounds to test the surface chemistry and subsequent ability to achieve electrochemical and photoelectrochemical charge transfer. Surface-tethered ferrocene groups exhibit good electron-transfer characteristics with thermal rates estimated at >1000 s(-1). Time-resolved surface photovoltage measurements using a ruthenium terpyridyl coordination compound demonstrate photoelectron charge transfer on time scales of nanoseconds or less, limited by the laser pulse width. The results demonstrate that the CuAAC "click" reaction can be used to form electrochemically and photoelectrochemically active molecular interfaces to SnO(2) and other metal oxide semiconductors.
我们展示了“点击”化学在将电活性和光电活性分子界面形成到 SnO(2) 纳米粒子薄膜中的应用。通过用光化学接枝将短链醇连接到表面，然后将其转化为表面叠氮基团，我们可以在金属氧化物表面上使用 Cu(I) 催化的叠氮-炔烃 [3 + 2] 环加成（CuAAC）反应，这是“点击”化学的一种形式。我们用三种模型化合物来测试表面化学和随后实现电化学和光电化学电荷转移的能力。表面固定的二茂铁基团表现出良好的电子转移特性，热速率估计大于 1000 s(-1)。使用钌三吡啶配合物进行的时间分辨表面光电压测量表明，光电子电荷转移在纳秒或更短的时间尺度上发生，受激光脉冲宽度限制。结果表明，CuAAC“点击”反应可用于将电活性和光电活性分子界面形成到 SnO(2) 和其他金属氧化物半导体上。
