Structural hierarchies at the molecular level can be determined by the hierarchies of interaction energies; in other words, for the generation of complex structures in several steps, significant differences in the interaction energetics are required.[1] The assembly of the first structural level needs to involve strong interactions between the molecular building blocks, whereas its subsequent extension without modification of the scaffold is conveniently ACHTUNGTRENNUNGachieved on the basis of weaker bonding forces. This applies both to supramolecular assemblies in solution and in air/vacuum and to fixed or spatially confined structures.[2] Herein, we provide such an example based on a surface organic network structure of unprecedented thermal stability. Crystal surfaces have served as initial scaffolds for the generation of such spatially addressable structures,[3] and the manipulation of single atoms and molecules has been ACHTUNGTRENNUNGachieved by scanning probe microscopy.[4, 5] More recently, extensive investigations into the controlled lateral manipulation of large molecules [6] possessing multiple and even partially addressable degrees of freedom have been reported.[7] The scanning tunneling microscopy (STM) tip was even used to induce chemical reactions,[8] for example, the Ullman reaction.[9]

We recently reported the formation of a highly stable, hexagonal molecular network generated by thermal dehydrogenation of 4, 9-diaminoperylene-quinone-3, 10-diimine (DPDI)[10] on a CuACHTUNGTRENNUNG (111) surface (Scheme 1).[11] By thermal activation, these molecules form autocomplementary hydrogen-bond donors/acceptors, which preposition themselves in the formation of the surface network. The highly regular honeycomb structure [12] is commensurate with the Cu substrate (in the form of a pACHTUNGTRENNUNG (10 10) superlattice with a lattice constant of 2.55 nm) and is thermally very stable (up to> 3008C) as a consequence of a combination of strong π bonding between the organic molecules and the surface metal atoms and resonance-assisted H bonding between the molecules. Due to its structural regularity and stability, this surface structure provides the ideal starting point for the assembly of functional hierarchical aggregates. The hexagonal “holes” in the network provide the opportunity for the local deposition and fixation of other molecules (Scheme 1). Figure 1 shows an STM image at 77 K of C60 and zinc octaethylporphyrin (ZnOEP) complexes subsequently deposited at ambient temperature on the previously prepared honeycomb network. Both C60 and ZnOEP are trapped and statistically distributed in the network. At this low tempera-