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A multivalent hexapod: conformational dynamics of six-legged molecules in self-assembled monolayers at a solid-liquid
Hong Xu1, Andrea Minoia, Zeljko Tomović
1Division of Molecular and Nano Materials, Department of Chemistry, and Institute for Nanoscale Physics and Chemistry, Katholieke Universiteit Leuven, Celestijnenlaan 200 F, B-3001, Leuven, Belgium.
ACS Nano
|April 14, 2009
Summary
This study introduces a molecular hexapod for observing molecular dynamics at interfaces. Defects, where legs detach from the surface, were found to influence molecular behavior and interactions.
Area of Science:
- Surface science
- Molecular dynamics
- Scanning probe microscopy
Background:
- Molecular hexapods with oligo(p-phenylene vinylene) (OPV) legs on a benzene core serve as model systems.
- Studying individual molecule dynamics in physisorbed self-assembled monolayers at solid-liquid interfaces is crucial.
Purpose of the Study:
- To investigate the intramolecular dynamics of molecular hexapods at a solid-liquid interface.
- To analyze the adsorption behavior and defect formation of hexapods on graphite surfaces.
Main Methods:
- Scanning tunneling microscopy (STM) was used to visualize molecular adsorption and defects.
- Molecular dynamics (MD) simulations were employed to understand molecular interactions and dynamics.
- Time-dependent STM experiments probed dynamic processes.
Main Results:
- Hexapods adsorb in both 2D crystalline and disordered domains.
- A significant percentage of molecules exhibit desorbed OPV legs, particularly in disordered domains (up to 80%).
- The presence of one desorbed leg promotes adjacent defects, indicating defect-mediated interactions.
Conclusions:
- Molecular hexapods are effective for studying interfacial dynamics.
- Defect formation (desorbed legs) is prevalent and influences molecular arrangement and interactions.
- The multivalent nature of hexapod-surface interactions was elucidated.
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