Self-assembly and tiling of a prochiral hydrogen-bonded network: bi-isonicotinic acid on coinage metal surfaces

Submolecular resolution scanning tunnelling microscopy and qPlus atomic force reveal that, close to thermal equilibrium, bi-isonicotinic acid (4,4'-COOH-2,2'-bpy) assembles into extended molecular rows on both Au(111) Ag(100) surfaces, driven primarily by the formation of OH··· N hydrogen bonds. Both intermolecular separation inter-row spacing for are identical within experimental uncertainty, highlighting that assembly networks metal surfaces is predominantly hydrogen-bonding potential energy variation due substrate has relatively little influence. Nonetheless, surface plays a key role in organisation: symmetry-breaking induces prochiral behaviour, which drives enantiomers form racemic mixture different handedness. We adapt tiling model previously introduced 2D tetracarboxylic derivatives [Blunt et al. Science 322, 1077 (2008)] system, providing insights growth kinetics attaining good agreement with morphologies observed experiment.