STM observation of zinc(II) bridled chiroporphyrin molecules on titanium dioxide surface

Zinc bridled chiroporphyrin (ZnBCP-8) molecules on a rutile titanium dioxide (TiO 2 )(110)–(1 × 1) surface were successfully observed by scanning tunneling microscopy (STM) under ultrahigh vacuum conditions. The molecules were selectively adsorbed on the surface apparently due to a molecule–substrate interaction. The origin of the interaction is thought to be Coulomb force between molecule and oxygen vacancy on the TiO 2 surface. STM imaging revealed a selective molecular orientation on the TiO 2 (110)–(1 × 1) structure. These results support the possibility of manipulating molecules on the surface and constructing well designed molecular structures by controlling the molecular–substrate and intermolecular interactions.