Bipyridine-mediated assembling characteristics of aromatic acid derivatives

Binary supramolecular assemblies formed by heterogeneous hydrogen bonds of O center dot center dot center dot H-O and N center dot center dot center dot H-O mediated by 4,4'bipytidine (Bpy) were observed using scanning tunneling microscopy (STM) on highly oriented pyrolytic graphite (HOPG) surfaces under ambient conditions. The building units of the assemblies could be attributed to thecombinatory molecular motifs of acid- bipyridine- acid formed through the strong N center dot center dot center dot H-O intermolecular hydrogen bonding.