Formation of Confined C60 Islands within Octanethiol Self-Assembled Monolayers on Au(111)

Confined C-60 islands have been grown within octanethiol self-assembled monolayers (SAMs) on the Au(111) surface. The structure of the C60 islands is investigated by use of scanning tunneling microscopy (STM), and a single ordered phase of the close-packed C-60 islands with a (2 root 3 x 2 root 3)R30 degrees structure is found. In the vicinity of the close-packed C-60 island there are loosely packed C-60 molecules which are mixed with the thiolate species. Floating C-60 on top of the SAM, in the form of either compact islands or individual molecules, is not found at room temperature and above. The diffusion of C-60 molecules is strongly controlled by the structure of the SAM, and the (root 3 x root 3)R30 degrees phase of the SAM is not permissible to diffusing C-60 molecules.