Molecular assembly of fullerene-conjugated phthalocyanine derivative on Au(111) at single molecular level

Molecular adlayers of doubly C(60)-conjugated phthalocyanine derivatives ((C(60))(2)NiPc) were examined on bare and zinc(II) octaethylporphyrin (ZnOEP)- and coronene-modified Au(111) surfaces. Electrochemical scanning tunneling microscopy (EC-STM) has revealed the structure of the (C(60))(2)NiPc adlayer at single molecular level. The (C(60))(2)NiPc adlayer is strongly influenced by the underlying organic layers, i.e., a disordered, a packed structure of (C(60))(2)NiPc was found on a clean Au(111) surface because of the strong interaction between (C(60))(2)NiPc molecule and Au(111) substrate, whereas a single (C(60))(2)NiPc molecule was clearly distinguished both on ZnOEP and coronene adlayers at a low coverage of (C(60))(2)NiPc molecules. The obtained results in the present study suggest that the underlying organic adlayers play an important role in the formation process of the (C(60))(2)NiPc molecule adlayer.