A study of planar anchor groups for graphene-based single-molecule electronics
A study of planar anchor groups for graphene-based single-molecule electronics
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DOI：
10.1063/1.4861941
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发表时间：
2014-02-07
影响因子：
4.4
通讯作者：
Chappell, David
中科院分区：
文献类型：
--
作者：
Bailey, Steven;Visontai, David;Chappell, David
为了确定用于单分子电子学的稳定平面锚基团家族，我们报告了吸附在石墨烯上的蒽和芘衍生物的两个家族的结合能的详细结果。我们发现，所有选择的具有供电子或接受电子取代基的衍生物与石墨烯的结合比母体非功能化的蒽或芘更强。结合能对取代基在石墨烯衬底上的详细原子排列非常敏感，导致-OH和-CN衍生物的结合能大于预期。此外，蒽和芘系列中结合能的排序并不简单地遵循取代基的电子亲和力。石墨烯表面旋转或位移的能垒远低于吸附的结合能，因此在室温下，尽管分子与石墨烯结合，但它们几乎可以自由地沿着石墨烯表面移动。结合电惰性侧链可以增加结合能，并且对这种侧链的构象很敏感。(C) 2014 AIP出版有限责任公司
To identify families of stable planar anchor groups for use in single molecule electronics, we report detailed results for the binding energies of two families of anthracene and pyrene derivatives adsorbed onto graphene. We find that all the selected derivatives functionalized with either electron donating or electron accepting substituents bind more strongly to graphene than the parent non-functionalized anthracene or pyrene. The binding energy is sensitive to the detailed atomic alignment of substituent groups over the graphene substrate leading to larger than expected binding energies for -OH and -CN derivatives. Furthermore, the ordering of the binding energies within the anthracene and pyrene series does not simply follow the electron affinities of the substituents. Energy barriers to rotation or displacement on the graphene surface are much lower than binding energies for adsorption and therefore at room temperature, although the molecules are bound to the graphene, they are almost free to move along the graphene surface. Binding energies can be increased by incorporating electrically inert side chains and are sensitive to the conformation of such chains. (C) 2014 AIP Publishing LLC.