Adlayers of Fullerene Monomer and [2 + 2]-Type Dimer on Au(111) in Aqueous Solution Studied by in Situ Scanning Tunneling Microscopy

Abstract

In situ scanning tunneling microscopy (STM) revealed that highly ordered adlayers of fullerene monomer (C60) and [2 + 2]-type dimer (C120) were formed on Au(111) by immersing the surface in benzene solution containing C60 or C120 molecules. High-resolution STM images allowed us to determine packing arrangements of C60 and C120 on a Au(111) surface in an aqueous HClO4 solution. The (2 3 × 2 3)R30°and the so-called in-phase structures of the C60 adlayer were found on the Au(111) surface, whereas the (2 3 × 4 3)R30°a nd (2 3 × 5 3)R30°structures were observed for the C120 dimer. Each C120 dimer was imaged in a dumbbell shape by in situ STM.

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

“…Similar results were obtained on the film prepared by immersing Au(111) into a C 60 -benzene solution in electrochemical environment using electrochemical scanning tunnelling microscopy (ECSTM) [12]. However, on Ag(111) surface [3, [7][8][9], STM images show that the C 60 monolayer exclusively forms (2 3 2 3)  R30° structure.…”

“…This value matches with the nearest neighbouring distance of C 60 in the bulk phase at 10.04 Å, suggesting the good commensurate between C 60 and Au(111) lattice. Based on these measurements further in combination with the previous reports [8][9][10][11][12], one may identify an oblique experimental unit cell of (2 3 2 3)  R30° for domain  and an "in-phase" struc- ture for domain .…”

Electrochemical STM investigation of C70, C60/C70 mixed fullerene and hydrogenated fullerene adlayers on Au(111) prepared using the electrochemical replacement method

“…Wet processes such as the spontaneous adsorption of fullerenes from organic solvent [23][24][25]32,33,35,38,39], solution evaporation [26], and the transfer of Langmuir (L) films from the air-water interface (Langmuir-Blodgett (LB) technique) [21,22,[27][28][29][30][31] have also proven equally successful. For the deposition of layers on substrates, however, wet processes are generally considered to be relatively milder techniques compared to dry processes.…”

“…For the deposition of layers on substrates, however, wet processes are generally considered to be relatively milder techniques compared to dry processes. For example, the in situ STM observation of fragile fullerene dimers and trimers, which are too unstable to apply by vapor deposition, were successfully achieved using a simple ''wet process" [31,32]. As an improved technique for the simple transfer of L films, we proposed the electrochemical replacement (ECR) method ( Fig.…”

Challenges and breakthroughs in recent research on self-assembly

“…Because of advances in probe microscopies, we can now observe directly images of individual molecules and their arrangements. Excellent images of various species such as aliphatic molecules [940][941][942], aromatic molecules [943][944][945][946][947][948][949][950][951], porphyrins and their families [952][953][954][955][956][957][958][959][960], fullerenes [961][962][963][964][965][966][967] and polymers [968] are now available. In addition, manipulation of molecular level processes has been demonstrated.…”