National Center for Nanoscience and Technology (NCNST), Beijing 100190, P R China.
Phys Chem Chem Phys. 2013 Aug 14;15(30):12510-5. doi: 10.1039/c3cp51586a.
In this paper, a novel core-modified porphyrin with meso-aryl substituents and phenanthrene-fused pyrrole rings (N2S2-OR) is synthesized. Scanning tunneling microscopy (STM) has been used to probe its self-assembly behavior on a highly-oriented pyrolytic graphite (HOPG) surface. Our STM results have shown that there is an obvious solvent-dependent self-assembly for the surface-confined target molecules. In n-tetradecane, N2S2-OR assembles into a perfect alternating structure. At the 1-phenyloctane-graphite interface, disordered structures are formed and nonperiodic alternation is observed, whereas the target molecule in 1-heptanoic acid is assumed to form homogeneous close-packed monolayers with no alternating. Interestingly, such solvent-dependent supramolecular assembled behavior also involves the structural transformation of the backbone of the core-modified porphyrin derivative from saddle to reversed-saddle in these three solvents with different polarities.
本文合成了一种具有间芳基取代基和菲并吡咯环的新型核修饰卟啉（N2S2-OR）。扫描隧道显微镜（STM）已被用于探测其在高度取向石墨（HOPG）表面上的自组装行为。我们的 STM 结果表明，对于表面受限的靶分子，存在明显的溶剂依赖性自组装。在正十四烷中，N2S2-OR 组装成完美的交替结构。在 1-苯基辛烷-石墨界面上，形成无序结构并观察到非周期性交替，而在 1-庚酸中的目标分子被认为形成无交替的均匀密堆积单层。有趣的是，这种溶剂依赖性超分子组装行为还涉及核心修饰卟啉衍生物骨架的结构从鞍形到这三种具有不同极性的溶剂中的反向鞍形的转变。
