Epitaxy-Induced Assembly and Enantiomeric Switching of an On-Surface Formed Dinuclear Organocobalt Complex.
Raphael HellwigTobias PaintnerZhi ChenMario RubenAri Paavo SeitsonenFlorian KlappenbergerHarald BruneJohannes V BarthPublished in: ACS nano (2017)
We report on the surface-guided synthesis of a dinuclear organocobalt complex, its self-assembly into a complex nanoarchitecture, and a single-molecule level investigation of its switching behavior. Initially, an organic layer is prepared by depositing hexakis((trimethylsilyl)ethynyl)-benzene under ultrahigh-vacuum conditions onto Ag(111). After Co dosage at 200 K, low-temperature scanning tunneling microscopy (STM) reveals an epitaxy-mediated organization mechanism of molecules and on-surface formed organometallic complexes. The dinuclear complexes contain two bis(η2-alkynyl) π-tweezer motifs, each stabilizing a single Co atom and express two enantiomers due to a conformation twist. The chirality is transferred to the two-dimensional architecture, whereby its Co adatoms are located at the corners of a 3.4.6.4 rhombitrihexagonal tessellation due to the systematic arrangement and anchoring of the complexes. Extensive density functional theory simulations support our interpretation of an epitaxy-guided surface tessellation and its chiral character. Additionally, STM tip-assisted manipulation experiments on isolated dinuclear complexes reveal controlled and reversible switching between the enantiomeric states via inelastic electron processes. After activation by bias pulses, structurally modified complexes display a distinctive Kondo feature attributed to metastable Co configurations.
Keyphrases
- single molecule
- density functional theory
- molecular dynamics
- capillary electrophoresis
- high resolution
- machine learning
- genome wide
- gene expression
- ionic liquid
- deep learning
- mass spectrometry
- molecular dynamics simulations
- optical coherence tomography
- high throughput
- signaling pathway
- high speed
- label free
- electron microscopy