Surface host-guest assembly as a bottom-up approach for the construction of functional molecular nanostructures

Surface host-guest assembly is a promising bottom-up approach to build up molecular nanostructures with good controllability. In the present study, we investigated the solvent effect on the host-guest assembly of 2,7,12-trihexyloxytruxene (Tr) with coronene by scanning tunneling microscopy at liquid/solid interfaces. The two-dimensional (2D) self-assembled networks of Tr are shown to accommodate coronene guest molecules on highly oriented pyrolytic graphite (HOPG) surfaces. In contrast to the similar 2D hexagonal self-assembly of Tr host template on HOPG in different solvents, the formation of host-guest nanostructures of coronene in Tr 2D network strongly depend on the polarity of the solvents. The thermodynamic equilibrium during the host-guest assembly process is discussed, and the solvent-guest interaction is proposed as a main contributor for the observed solvent effect in the 2D host-guest self-assembly process.