Center for Nanophase Materials Sciences, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States.
J Am Chem Soc. 2013 Apr 3;135(13):4922-5. doi: 10.1021/ja4000905. Epub 2013 Mar 26.
Using scanning tunneling microscopy we observed reaction products of two chemisorbed thiolate species, methylthiolate and phenylthiolate, on the Au(111) surface. Despite the apparent stability, organometallic complexes of methyl- and phenylthiolate with the gold-adatom (RS-Au-SR, with R as the hydrocarbon group) undergo a stoichiometric exchange reaction, forming hybridized CH3S-Au-SPh complexes. Complementary density functional theory calculations suggest that the reaction is most likely mediated by a monothiolate RS-Au complex bonded to the gold surface, which forms a trithiolate RS-Au-(SR)-Au-SR complex as a key intermediate. This work therefore reveals the novel chemical reactivity of the low-coverage "striped" phase of alkanethiols on gold and strongly points to the involvement of monoadatom thiolate intermediates in this reaction. By extension, such intermediates may be involved in the self-assembly process itself, shedding new light on this long-standing problem.
我们使用扫描隧道显微镜观察了两种化学吸附硫醇物种（甲基硫醇和苯基硫醇）在 Au(111)表面的反应产物。尽管表面上很稳定，但甲基硫醇和苯基硫醇与金原子（RS-Au-SR，其中 R 为烃基）的有机金属配合物会发生化学计量交换反应，形成杂化的 CH3S-Au-SPh 配合物。补充的密度泛函理论计算表明，该反应很可能是由与金表面键合的单硫醇 RS-Au 配合物介导的，该配合物形成三硫醇 RS-Au-(SR)-Au-SR 配合物作为关键中间体。因此，这项工作揭示了金上烷硫醇低覆盖率“条纹”相的新化学反应性，并强烈指出单原子硫醇中间体在此反应中的参与。由此延伸，这些中间体可能参与了自组装过程本身，为这个长期存在的问题提供了新的见解。
