Molecular imaging of reductive coupling reactions: interstitial-mediated coupling of benzaldehyde on reduced TiO2(110).
Molecular imaging of reductive coupling reactions: interstitial-mediated coupling of benzaldehyde on reduced TiO2(110).
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DOI：
10.1021/nn103144u
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发表时间：
2011-01
期刊：
影响因子：
17.1
通讯作者：
Lauren Benz;J. Haubrich;Stephen C. Jensen;C. Friend
中科院分区：
文献类型：
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作者：
Lauren Benz;J. Haubrich;Stephen C. Jensen;C. Friend
我们报告了第一个可视化的反应性中间体形成的耦合两个分子的表面上形成的二醇盐苯甲醛耦合TiO（2）（110）。的二醇盐，使用扫描隧道显微镜（STM）成像，减少到气态芪加热到10400 K后，留下两个氧原子，与减少Ti的化合物迁移到表面反应，相反的流行的预期，强键在含氧分子反应，只有在表面的氧空位。我们的工作进一步提供了实验和理论证据，钛化合物驱动二醇盐中间体的形成。最初的移动的单体迁移在一起，形成成对的功能，确定为二醇盐，键合在两个相邻的五坐标钛原子的表面上。我们的工作具有广泛的重要性，因为它表明了在分子尺度上成像反应物物种的分布和键合构型的可能性，这是理解表面反应和反应过程中表面形态发展的关键部分。
We report the first visualization of a reactive intermediate formed from coupling two molecules on a surface-a diolate formed from benzaldehyde coupling on TiO(2)(110). The diolate, imaged using scanning tunneling microscopy (STM), is reduced to gaseous stilbene upon heating to ∼400 K, leaving behind two oxygen atoms that react with reduced Ti interstitials that migrate to the surface, contrary to the popular expectation that strong bonds in oxygenated molecules react only with oxygen vacancies at the surface. Our work further provides both experimental and theoretical evidence that Ti interstitials drive the formation of diolate intermediates. Initially mobile monomers migrate together to form paired features, identified as diolates that bond over two adjacent five-coordiante Ti atoms on the surface. Our work is of broad importance because it demonstrates the possibility of imaging the distribution and bonding configurations of reactant species on a molecular scale, which is a critical part of understanding surface reactions and the development of surface morphology during the course of reaction.