Flexible Self-Assembled Molecular Templates on Graphene

Research output: Contribution to journalArticleScientificpeer-review

Researchers

Research units

  • Kanazawa University

Abstract

We report on molecular self-assembly employing a host-guest architecture to pattern the growth of molecules on graphene model surface. Under suitable conditions, the 1,3,5-benzenetribenzoic acid (BTB) self-assembles into an extended honeycomb mesh on graphene on Ir(111), with the molecules in the network being stabilized by linear hydrogen bonds between the carboxylic groups. The nanopores of the mesh are used to host and govern the assembly of cobalt phthalocyanine (CoPC) guest molecules. We characterize the assembled structures structurally and electronically using low-temperature scanning tunneling microscopy (STM) and density functional theory (DFT) calculations. At a coverage higher than one CoPc per pore, the flexible hydrogen bonds of the host network undergo stretching to accommodate two CoPCs in a single pore. When the pores are uniformly doubly occupied, the guest molecules arrange into a herringbone pattern. This minimizes the energy cost associated with the stretching and twisting of the hydrogen bonds between the BTB molecules. The phenomenon observed here can be used to tailor molecular assemblies on graphene to controllably modify its properties. In addition, it allows the formation of guest monomers and dimers stabilized mechanically on the surface of graphene, an archetypical weakly interacting substrate.

Details

Original languageEnglish
Pages (from-to)8772-8780
Number of pages9
JournalJournal of Physical Chemistry C
Volume120
Issue number16
Publication statusPublished - 28 Apr 2016
MoE publication typeA1 Journal article-refereed

ID: 4301041