The Side Chain Makes the Difference: Investigation of the 2D Self-Assembly of 1,3,5-Tris[4-(4-pyridinyl)phenyl]benzene Derivatives by Scanning Tunneling Microscopy
作者:Daniel Trawny、Lucie Vandromme、Jürgen P. Rabe、Hans-Ulrich Reissig
DOI:10.1002/ejoc.201402178
日期:2014.8
functionalized compound arms, Suzuki couplings were applied. The crucial introduction of the pyridine C-2 and C-6 substituents occurred by Fe(acac)3-catalyzed alkylations (acac = acetylacetonate). The preparation of the C3-symmetrical compound involved an alternating sequence of halogenations and coupling reactions. The self-assembly behavior of the four resulting star-shaped compounds at the interface
报告了一系列具有吡啶端基的 D3h 或 C3h 对称星形化合物的灵活和直接合成。在所有情况下,相应的芳基甲基酮的酸介导的环缩合反应提供了中心苯环。对于功能化复合臂的先前制备,应用了铃木偶联。吡啶 C-2 和 C-6 取代基的关键引入发生在 Fe(acac)3 催化的烷基化反应(acac = 乙酰丙酮化物)中。C3-对称化合物的制备涉及卤化和偶联反应的交替序列。通过扫描隧道显微镜 (STM) 研究了四种所得星形化合物在 1-苯基辛烷和高取向热解石墨 (HOPG) 基面之间的界面处的自组装行为。我们发现自组装单分子层的结构强烈依赖于所研究化合物的取代模式。从 D3h- 到 C3h 对称化合物的对称性降低导致完全不同的自组装行为,从六边形排列变为层状排列。