Bis(terpyridine)derivatives (BTP) form highly ordered hydrogen-bonded 2D networks on solid surfaces.1-4 The preferred hydrogen bond configurations and thus the resulting structures are steered via the positions of the nitrogen atoms within the BTP molecules. Elaborate synthesis procedures allow varying these positions without altering the footprint shape of the molecules.1 On smooth surfaces like graphite or metal single crystals, the molecule-substrate interactions play a secondary role for the structures, mainly by determining the orientations of the molecules and thus of the ordered networks.2-4 In this contribution, we will demonstrate that more pronounced template effects arise for substrates where the molecule-substrate interaction laterally varies at nm-scales. As an example, we will show the ordering behaviour of two different types of BTP molecules on Graphene monolayers grown on Ru(0001). The moiré-type pattern of these surfaces has a periodicity of 3 nm, i.e., in the order of the BTP dimensions and the network meshes they usually form. Submolecularly resolved STM images show that the BTP molecules are confined to the valleys of the graphene ripple structure. We will compare the resulting supramolecular 1D and 2D assemblies to the ordered 2D networks formed by the same molecules on smooth substrates, and we will discuss in how far the template effect can be quantitatively explained by a lateral modulation of the van der Waals interactions due to the height corrugation of the Graphene sheet.5

 

1C. Meier et al., J Phys Chem B 109 (2005) 21015.

2 M. Roos et al., Phys. Chem. Chem. Phys. 9 (2007) 5672.

3 H. E. Hoster et al., Langmuir 23 (2007) 11570.

4 T. Waldmann et al., ChemPhysChem 11 (2010) 1513.5 W. Moritz et al., Phys. Rev. Lett. 104 (2010) 136102.