Publishing type：Research paper (scientific journal)   Publisher：Wiley  

Abstract

Artificial molecular machines, especially when based on wheel‐and‐axle complexes, can generate mechanical motions in response to external stimuli. Ferrocene (Fc) is a key component, but it decomposes at 300 K on metal surfaces. Here, a novel method is presented to construct and control the molecular complex composed of ammonium‐linked ferrocene (Fc‐amm) and tetrabrominated crown ether (BrCR) on a Cu(111) surface. Fc‐amm molecules are periodically arranged on a BrCR monolayer film and imaged using scanning tunneling microscopy and spectroscopy. A lateral motion of the Fc groups by ≈0.1 nm is observed for pairs of “edge‐on” Fc‐amm molecules upon hole injection. This sliding motion is reversible and controlled by the applied voltage. Theoretical analysis indicates that the motion is caused by increased Coulomb repulsion of the hole‐doped Fc‐amm+ ions and accompanied by a weakening of CH‐π interactions. These findings open new avenues for developing nanomolecular devices using on‐surface bottom‐up processes.

DOI： 10.1002/smll.202408217

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Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

Abstract

Moiré superlattices consisting of two-dimensional materials have attracted immense attention because of emergent phenomena such as flat band-induced Mott insulating states and unconventional superconductivity. However, the effects of spin-orbit coupling on these materials have not yet been fully explored. Here, we show that single- and double-bilayer antimony honeycomb lattices, referred to as antimonene, form moiré superlattices on a Bi(111) substrate due to lattice mismatch. Scanning tunnelling microscopy (STM) measurements reveal the presence of spectral peaks near the Fermi level, which are spatially modulated with the moiré period. Angle-resolved photoemission spectroscopy (ARPES) combined with density functional theory calculations clarify the surface band structure with saddle points near the Fermi level, which allows us to attribute the observed STM spectral peaks to the van Hove singularity. Moreover, spin-resolved ARPES measurements reveal that the observed surface states are Rashba-type spin-polarized. The present work has significant implications in that Fermi surface instability and symmetry breaking may emerge at low temperatures, where the spin degree of freedom and electron correlation also play important roles.

DOI： 10.1038/s43246-024-00615-z

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Other Link： https://www.nature.com/articles/s43246-024-00615-z

Authorship：Lead author   Publishing type：Research paper (scientific journal)  

DOI： 10.1021/acsnano.4c04496

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Publishing type：Research paper (scientific journal)   Publisher：Royal Society of Chemistry (RSC)  

Surface polymerization was conducted by utilizing a two-dimensional (2D) self-assembled monolayer array of tetrabrominated crown ether precursors on Cu(111) through an intermediate Ullmann reaction, resulting in the formation of a 2D random network with winding stripes.

DOI： 10.1039/d3nh00586k

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Publishing type：Research paper (scientific journal)   Publisher：Royal Society of Chemistry (RSC)  

We report an on-surface growth of transition-metal nanoclusters using a 2D self-assembled monolayer (SAM) crown ether ring molecular array prepared on Cu(111).

DOI： 10.1039/d3tc03339b

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Award type：Award from Japanese society, conference, symposium, etc.  Country：Japan

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Award type：Award from international society, conference, symposium, etc.  Country：Japan

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Award type：Award from Japanese society, conference, symposium, etc.  Country：Japan

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Award type：Award from international society, conference, symposium, etc.  Country：Taiwan, Province of China

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