- Selective Assembly of Porphyrin Molecules into Supramolecular Aggregates on a Surface - Takashi YOKOYAMA, Shiyoshi YOKOYAMA, Toshiya KAMIKADO, Yoshishige OKUNO and Shinro MASHIKO The rational construction of desired molecular nanostructures should be required to realize molecular nanodevices, ideally with these structures supported on suitable substrates. We report the formation of surface-supported supra-molecular structures whose size and aggregations patterns are rationally controlled by using selective and directional in-termolecular interactions between cyanophenyl substituents. Using low-temperature scanning tunneling microscopy and molecular orbital calculations, we have analyzed the conformation and arrangement of adsorbed porphyrin molecules on Au(111) surface. In case of cyanophenyl-substituted porphyrins, monomers, trimers, tetramers, or extended wire-like structures is selectively formed on the Au(111) surface by modifying substituents. These structures should be induced by local dipole-dipole interaction between cyanophenyl substituents. Our findings indicate that the rational design and construction of surface-supported supramolecular architectures will be allowed by introducing non-covalent interac- tions. |