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Updated: May 27, 2026
05:51
Isotopic Effect in Double Proton Transfer Process of Porphycene Investigated by Enhanced QM/MM Method
Published on: July 19, 2019
Molecular rotation in self-assembled multidecker porphyrin complexes.
Hiroyuki Tanaka1, Tomohiro Ikeda, Masayuki Takeuchi
1The Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Osaka 567-0047, Japan. hrtanaka@sanken.osaka-u.ac.jp
ACS Nano
|November 15, 2011
Summary
Researchers created ordered arrays of cerium double-decker porphyrins (CeDDP) and lanthanum triple-decker porphyrins (LaTDP) on a gold surface. STM imaging revealed distinct rotational behaviors of the top porphyrin ligands, paving the way for molecular machines.
Area of Science:
- Supramolecular Chemistry
- Surface Science
- Nanotechnology
Background:
- Multidecker porphyrin complexes offer unique electronic and structural properties.
- Controlling the arrangement and behavior of molecules on surfaces is crucial for nanoscale device development.
Purpose of the Study:
- To investigate the self-assembly and surface behavior of alkyl chain-substituted cerium double-decker porphyrins (CeDDP) and lanthanum triple-decker porphyrins (LaTDP) on Au(111).
- To characterize the internal structure and rotational dynamics of these complexes using low-temperature scanning tunneling microscopy (STM).
Main Methods:
- Pulse injection deposition for creating monolayer arrays of CeDDP and LaTDP on Au(111).
- Low-temperature scanning tunneling microscopy (LT-STM) for high-resolution imaging and topographic measurements.
Main Results:
- Well-defined two-dimensional arrays of intact CeDDP and LaTDP complexes were successfully formed on the Au(111) substrate.
- STM imaging clearly visualized the internal structures and allowed measurement of topographic heights.
- The top porphyrin ligand in CeDDP showed minimal rotation, while the top ligand in LaTDP exhibited flip-flop rotation even under nondestructive imaging conditions.
Conclusions:
- The distinct rotational dynamics of porphyrin ligands in CeDDP and LaTDP on surfaces are controllable.
- These findings demonstrate potential for applications in molecular-scale mechanical machines and single-molecule data storage memory.
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