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由于其独特的分子构型和电子结构,碗烯被认为是组成有机分子电子器件的一种重要的结构单元。在不同金属表面上单一组分的碗烯或其衍生物进行自组装的行为,及其所形成自组装薄膜的电子结构已经被广泛研究。这里我们利用低温扫描隧道显微镜(LT-STM),对全氟酞菁铜和碗烯两种组分在高定向热解石墨和银(111)两种不同衬底上的自组装结构进行了报道。在石墨衬底上,全氟酞菁铜和碗烯分子间形成的氢键成为双分子网络结构能够形成的关键;同时,由于这种分子间氢键的存在,碗烯分子大多采取“开口朝下”的空间构型,以保证分子间氢键最大限度的形成。但在银衬底上观察到的碗烯分子则随机采取“开口向上”或“开口向下”两种构型,并没有一种优势构型的存在。我们认为此时银(111)衬底和有机分子间强烈的相互作用限制了碗烯两种构型之间的翻转,使得碗烯分子一旦被吸附就只能保持其原本的构型,从而导致了在结果上两种构型的随机分布。
Due to its unique molecular configuration and electronic structure, it is considered as one of the most important structural elements in organic molecular electronic devices. The self-assembly of a single component of alkene or its derivatives on different metal surfaces and the electronic structure of the self-assembled films formed by them have been extensively investigated. Here, we report the self-assembly of two components of perfluorophthalocyanine and alkene on two different substrates of highly oriented pyrolytic graphite and silver (111) using a low temperature scanning tunneling microscope (LT-STM) . On the graphite substrate, the hydrogen bonds formed between the copper perfluorophthalocyanine and the alkene molecules become the key to the formation of the bimolecular network structure. At the same time, most of the molecules of the alkene molecules adopt the “ Downward ”space configuration to ensure the maximum formation of hydrogen bonds between molecules. However, the observed molecular structure of the alkene on the silver substrate randomly adopts the two configurations of “opening up” or “opening down”, and there is no existence of a dominant configuration. We believe that the strong interaction between the silver (111) substrate and the organic molecules at this time limits the turnover between the two configurations of the alkene so that once it has been adsorbed it will retain its original configuration, resulting in The result is a random distribution of the two configurations.