Soukiassian Laetitia, Mayne Andrew J, Comtet Geneviève, Hellner Lucette, Dujardin Gérald, Gourdon André
Laboratoire de Photophysique Moléculaire, CNRS, UPR 3361, Bâtiment 210, Université de Paris-Sud, 91405 Orsay, France.
J Chem Phys. 2005 Apr 1;122(13):134704. doi: 10.1063/1.1874972.
We have studied the adsorption of the polyaromatic molecule 1,4"-paratriphenyldimethylacetone, which we have nicknamed Trima. The originality of this linear molecule is that it was designed and synthesized to have two functionalities. First, chemisorb itself to the surface by its two ends rather like a bridge. Second, the central part of the molecule could then be rotated by injecting electrons with the tip of the scanning tunneling microscope (STM). The length of the molecule corresponds exactly to the spacing between five dimers in a row on the Si(100)-2 x 1 surface. We found that the molecule adsorbs as expected on the clean silicon surface by using complementary STM and synchrotron radiation studies. Manipulation of individual molecules with the STM tip showed selective internal modifications that were highly voltage dependent. These manipulations were found to be compatible with an electronic excitation of the pi-pi* transition of the molecule.
我们研究了多芳族分子1,4"-对三联苯二甲基丙酮（我们将其昵称为Trima）的吸附情况。这种线性分子的独特之处在于，它被设计合成具有两种功能。其一，它能通过两端像桥一样自身化学吸附到表面。其二，然后可以通过用扫描隧道显微镜（STM）的针尖注入电子来旋转分子的中心部分。该分子的长度恰好对应于Si(100)-2×1表面上连续五个二聚体之间的间距。我们发现，通过结合STM和同步辐射研究，该分子如预期那样吸附在清洁的硅表面上。用STM针尖对单个分子进行操纵显示出高度依赖电压的选择性内部修饰。发现这些操纵与分子的π-π*跃迁的电子激发是相容的。
