Hulsken Bas, Van Hameren Richard, Gerritsen Jan W, Khoury Tony, Thordarson Pall, Crossley Maxwell J, Rowan Alan E, Nolte Roeland J M, Elemans Johannes A A W, Speller Sylvia
Nat Nanotechnol. 2007 May;2(5):285-9. doi: 10.1038/nnano.2007.106. Epub 2007 Apr 22.
Many chemical reactions are catalysed by metal complexes, and insight into their mechanisms is essential for the design of future catalysts. A variety of conventional spectroscopic techniques are available for the study of reaction mechanisms at the ensemble level, and, only recently, fluorescence microscopy techniques have been applied to monitor single chemical reactions carried out on crystal faces and by enzymes. With scanning tunnelling microscopy (STM) it has become possible to obtain, during chemical reactions, spatial information at the atomic level. The majority of these STM studies have been carried out under ultrahigh vacuum, far removed from conditions encountered in laboratory processes. Here we report the single-molecule imaging of oxidation catalysis by monitoring, with STM, individual manganese porphyrin catalysts, in real time, at a liquid-solid interface. It is found that the oxygen atoms from an O2 molecule are bound to adjacent porphyrin catalysts on the surface before their incorporation into an alkene substrate.
许多化学反应由金属配合物催化，深入了解其反应机理对于未来催化剂的设计至关重要。有多种传统光谱技术可用于在整体水平上研究反应机理，并且直到最近，荧光显微镜技术才被应用于监测在晶体表面和酶催化下进行的单个化学反应。借助扫描隧道显微镜（STM），在化学反应过程中获得原子水平的空间信息已成为可能。这些STM研究大多是在超高真空下进行的，与实验室过程中遇到的条件相差甚远。在此，我们报告了通过在液 - 固界面实时用STM监测单个锰卟啉催化剂来实现氧化催化的单分子成像。研究发现，O₂分子中的氧原子在并入烯烃底物之前先与表面相邻的卟啉催化剂结合。
