Department of Physical Chemistry, Fritz-Haber-Institute of the Max-Planck-Society, D-14195 Berlin, Germany.
J Phys Condens Matter. 2012 Oct 3;24(39):394013. doi: 10.1088/0953-8984/24/39/394013. Epub 2012 Sep 11.
Three different molecules, each containing two azobenzene switching units, were synthesized, successfully deposited onto a Au(111) surface by sublimation and studied by scanning tunneling microscopy at low temperatures. To investigate the influence of electronic coupling between the switching units as well as to the surface, the two azo moieties were connected either via π-conjugated para-phenylene or decoupling meta-phenylene bridges, and the number of tert-butyl groups was varied in the meta-phenylene-linked derivatives. Single molecules were found to be intact after deposition as identified by their characteristic appearance in STM images. Due to their mobility on the Au(111) surface at room temperature, the molecules spontaneously formed self-organized molecular arrangements that reflected their chemical structure. While lateral displacement of the molecules was accomplished by manipulation, trans-cis isomerization processes, typical for azobenzene switches, could not be induced.
三种不同的分子，每个分子都包含两个重氮苯开关单元，被成功地通过升华法沉积到 Au(111)表面上，并在低温下通过扫描隧道显微镜进行了研究。为了研究开关单元之间以及与表面的电子耦合的影响，两个偶氮部分通过π共轭的对苯撑或去耦的间苯撑桥连接，并且在间苯撑连接的衍生物中改变了叔丁基的数量。通过 STM 图像的特征外观，发现单分子在沉积后仍然完整，这表明它们没有受到损伤。由于它们在室温下在 Au(111)表面上的迁移性，分子自发地形成了反映其化学结构的自组织分子排列。虽然通过操纵可以实现分子的横向位移，但不能诱导典型的重氮苯开关的顺反异构化过程。
