Thermally Stable Array of Discrete C 60 s on a Two-Dimensional Crystalline Adlayer of Macrocycles both in Vacuo and under Ambient Pressure.

A periodic monolayer array of discrete C 60 s was generated on an atomically flat Au(111) surface with the aid of a template adlayer. The template was a two-dimensional (2D) array of molecular pits prepared on an Au(111) surface through 2D crystallization of shape-persistent macrocycles composed of four carbazole and four salphens/Ni-salphens with a 1 nm hollow. Scanning tunneling microscopy imaging under ultra-high vacuum revealed that the square-shaped macrocycles, with 1.5 nm sides, were arranged with a periodic spacing of approximately 4.0 nm on the Au(111) surface, where the orientation and periodicity of the macrocycles were dependent on their chemical structures. After sublimation of C 60 s onto the adlayer, a single C 60 molecule was entrapped in each pit, and an ordered molecular array of C 60 s was attained with a pattern similar to that of the macrocycles. The periodic pattern of C 60 s on the surface was thermally stable up to approximately 200 °C, even under ambient pressure. Scanning tunneling spectroscopy suggested the existence of an electronic interaction between the C 60 s and the Au(111) surface that was influenced by the macrocycle template on the surface.