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The cooperative effect of hydrogen and halogen bonds on the 2-dimensional molecular arrangement of highly oriented pyrolytic graphite has been studied by scanning tunneling microscopy. The scanning tunneling microscopy observations demonstrate that the self-assembled hydrogen-bonded molecular chicken-wire networks of trimesic acid have been significantly transformed after annealing and the introduction of tribromobenzene guest molecules. Bromine atoms and carboxyl groups were found to form 2 different multicomponent structures via hydrogen and halogen bonds. Owing to the effect of halogen and hydrogen bonds, tribromobenzene with trimesic acid formed the 3-fold symmetry networks. [ABSTRACT FROM AUTHOR]

The assembled structures of triangular symmetrically shape molecules with three functional groups, trimesic acid (TMA) and melamine, have been investigated by scanning tunneling microscopy on Highly Oriented Pyrolytic Graphite (HOPG) in ambient. Hexagonal porous structures are formed by these molecules and the cavity of the assembled structure becomes bigger when larger molecules are used as building blocks. The cavity within the assembled structure formed by TMA is bigger enough to host guest molecule. [ABSTRACT FROM AUTHOR]

The molecular self-assembly of deoxyribonucleic acid (DNA) plays an important role in understanding how nucleic acids form and can be exploited to construct nanostructures. In this study, scanning tunneling microscopy (STM) was used to observe nanostructures that form from co-adsorption of the guanine (G) and cytosine (C) complementary DNA bases on a highly oriented pyrolytic graphite surface. The high-resolution STM images show that the well-ordered co-adsorption structures are attributed to the rows formed from Watson–Crick G–C pairs, which are distinct from the structures observed for individual G–C components. The observed co-adsorption structure was modeled by density functional theory calculations, which provide information on the intermolecular interactions underlying its formation. [ABSTRACT FROM AUTHOR]

The monolayer self-assembled porous supramolecular networks of p-terphenyl-3,5,3′′,5′′-tetra-carboxylic acid (TPTC) that stabilized by intermolecular hydrogen bonding between four carboxyl groups at nonanoic acid/graphite interface were constructed. Scanning tunneling microscopy (STM) demonstrates that the guest molecules coronene (COR) adsorption in the pores of TPTC monolayer network. Furthermore, TPTC molecules can form the bilayer supramolecular framework and the trapping of COR guest molecules in both layers. [ABSTRACT FROM AUTHOR]