2D-Highly Ordered Epitaxial Adlayers of Fullerene, Fullerene oligomer and Fullerene Polymers Prepared by "Wet Process"

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"Wet process" techniques, which consisted of the simple transfer of Langmuir films, were developed and investigated in order to form highly-ordered epitaxial adlayers of fullerene, their derivatives and other aromatic molecules on single crystal metal surfaces.We found that the simple transfer of Langmuir films at the air-water interface allowed us to prepare epitaxial adlayers of fullerenes on Au(111) surfaces with ambient conditions. Furthermore, the improved "wet process" method, "electrochemical replacement method" was proposed. The method consists of the transfer of Langmuir films of C_60 onto iodine-modified Au(111) surfaces at air-water interface and followed by the electrochemical removal and the replacement from iodine adlayers to C_60 adlayers in solution. The C_60 adlayers prepared by this method showed excellent quality and uniformity, and they were essentially same as epitaxial adlayers prepared by sublimation. A highly-ordered epitaxial adlayer of coronene on the Au(111) surface was also prepared by the technique.The structural identification of isomers of the novel carbon allotrope C_190, that is, the trimer of fullerene C_60, prepared by the mechanochemical reaction of C_60 under "high-speed vibration milling" conditions were demonstrated, for the first resolution STM imaging. The results of the present STM technique clearly provide the visual evidence that an HPLC-separeted fraction is composed of only an isomer with "cyclic triangular" shape while another fraction consists of totally different isomers with "extended" structures. These results are in good agreement with theoretical prediction.