Structure and Epitaxial Registry on Graphite of a Series of Nanoporous Self-Assembled Molecular Monolayers

We have analyzed by STM the detailed structures of a series of nanoporous honeycomb networks stabilized by alkyl chain interdigitation on graphite at the liquid−solid interface, that is, clip-like noncovalent bonding. The variations observed as a function of the length of the peripheral aliphatic chains show that the assembly is directed not only by lateral intermolecular interactions but also by the adsorption site on the substrate. We derive an atomically accurate model for the registry with graphite of our nanoporous model series of systems. In full agreement with the quantitative model, the pore areas vary step-by-step by more than one order of magnitude along the whole series while preserving the detailed features of the graphite-induced alkyl chain interdigitation. The largest pores observed correspond to a ratio of uncovered substrate area as large as 35%.