Coadsorption-induced reconstruction of supramolecular assembly characteristics

A host supramolecular structure consisting of bis-(2,2':6',2"-terpyridine)-4'-oxyhexadecane (BT-O-C16) is shown to respond to coadsorbed molecules in dramatic ways, as observed by scanning tunneling microscopy (STM) on a highly oriented pyrolytic graphite (HOPG) surface under ambient conditions. Interestingly, the lattice parameter of the triphenylene-filled complex differs significantly from that of the coronene-filled one, although the triphenylene and coronene molecules are nearly the same size. The STM study and density functional theory calculations reveal that intermolecular hydrogen-bond interactions play an essential role in forming the assembly structures. The different electronic properties of coronene and triphenylene molecules are responsible for the difference in lattice parameters and consequently for the difference in filling behaviors in the coronene/BT-O-C16 and triphenylene/BT-O-C16 binary systems.