Adsorption and dynamics of long-range interacting fullerenes in a flexible, two-dimensional, nanoporous porphyrin network

Herein, a detailed investigation of the adsorption and dynamics of C-60 and C-70 fullerenes hosted in a self-assembled, two-dimensional, nanoporous porphyrin network on a solid Ag surface is presented. Time-resolved scanning tunneling microscopy (STM) studies of these supramolecular systems at the molecular scale reveal distinct host-guest interactions giving rise to a pronounced dissimilar mobility of the two fullerenes within the porphyrin network. Furthermore, long range coverage-dependant interactions between the all-carbon guests, which clearly affect their mobility and are likely mediated by a complex mechanism involving the Ag substrate and the flexible porphyrin host network, are observed. At increased fullerene coverage, this unprecedented interplay results in the formation of large fullerene chains and islands. By applying a lattice gas model with nearest-neighbour interactions and by evaluating the fullerence-pair distribution functions, the respective coverage-dependant guest-guest interaction energies are estimated.