ECSTM study of adsorption of C60, C70, C86 and Y@C82 on Au(111)

Abstract

The adsorption of a variety of fullerenes (C 60 , C 70 , C 86 , Y@C 82 ) on Au(111) electrode surfaces was comprehensively investigated in 0.1 M HClO 4 by electrochemical scanning tunneling microscopy (ECSTM). In the ordered C 60 's adlayer, C 60 molecules formed either (2 3 2 3)  or "in-phase" structure. The high resolution STM image shows that the C 60 cage is not simply round but shows a bifurcated feature. The adsorption orientation of C 60 on Au (111) is tentatively suggested. In the ordered C 70 's adlayer, the perpendicular fullerene molecules are the main adsorption mode and form (2 3 2 3)  structure. However, for C 86 and Y@C 82 , the ordered adlayer could not be obtained on Au(111) under the present condition. These differences may be due to the different molecular shapes and sizes, and the encapsulated metal atom which affects the lattice matches with the substrate. The adsorption of fullerene molecules on Au(111) from disorder to order could be tuned simply by steering the dimensional sizes or shapes of the fullerenes used.

In-situ STM observation of the phase transition of two-dimensional 2,5-distyrylpyrazine nanostructure adsorbed on Au(111) in an electrochemical environment

“…Great efforts have been made to fabricate nanostructures using various techniques, including the LangmuirBlodgett method, sol-gel synthesis, electrochemical deposition, chemical vapor deposition, and self-assembly [5,6]. In particular, the self-assembly technique has been widely used to prepare artificial nanostructures, and has become one of the major "bottom-up" approaches to construct molecular architectures [7]. Molecules in self-assembled monolayers (SAMs) take on special orientations, and can form well-defined arrays, depending on the interactions between the molecules and the substrate and the neighboring molecules.…”