Designing functionalized porphyrins capable of pseudo-2D self-assembly on surfaces

A crystallography-instructed strategy to highly ordered layering of porphyrins with different topologies on HOPG is developed based on meso-tetraarylporphyrins bearing 2-ethoxyethanol side chains as "sticky ends". These sticky ends are capable of displaying directive hydrogen bonding motifs with the inherent D4h symmetry of the porphyrins. Solvent effects are shown to have an important role in fabricating the adsorption. Metalation and subsequent axial ligation was a key controlling factor in the topology of the layer, leading to pseudo-2D structures on HOPG.