After the synthesis and observation of a wheelbarrow molecule in 2005 (a molecule composed of a rigid board, two legs ad two wheels), researchers have shown in 2007 that when two wheels are mounted on an axle, one of them is able to rotate under the push of the STM tip. They succeeded in controlling the direction of the rotation, which opens the way to the synthesis of functional nanovehicles. Experimentally speaking, the molecules were carefully deposited onto a very clean copper surface, and observed by the means of an STM. The STM tip is used both as a probe to capture an "image" and as a nano-sized finger to trigger the the rotation of the wheel, being placed in the perfect position for that purpose.
- © CEMES-CNRS
Recently, we have synthesized polycyclic aromatic hydrocarbons nanovehicles designed by analogy with macroscopic vehicles. The synthesis of two new chassis has been achieved, both including a dedicated cargo zone.
- © G. Rapenne CEMES, CNRS/UPS
In april 2017, GNS participated to its nanocar race with one of these nanovehicles, whose chemical structure was based on a central curved chassis and four wheels. The molecules were flash sublimated on an Au(111) surface and imaged at low temperature using the scanning tunneling microscope of the LT-UHV 4-STM dedicated to its drive. The curved conformation of the chassis and the consequent moderate interactions of the four wheels with the Au(111) surface have been observed. The dI/dV constant current maps of the tunneling electronic resonances close to the Au(111) Fermi level were recorded to identify the potential energy entry port on the molecular skeleton to trigger and control a driving of the molecule on the Au(111) surface.
A lateral pushing mode of molecular manipulation and the consequent recording of the manipulation signals confirm that the wheels can step by step rotate while passing over the Au(111) surface native herringbone reconstructions. Switching a phenyl holding a wheel to the chassis on a given axle was not observed for triggering a lateral molecular motion inelastically. This points out the necessity to encode the sequence of the required wheels action on the profile of potential energy surface of the excited states to be able to drive a molecule-vehicle.
In 2018, GNS announced the organization of the second edition of the International nano-car race for spring 2021 under the MEMO (Mechanics with molecule(s)) European project (www.memo-project.eu/flatCMS/index.php/Nanocar-Race-II). The GNS Toulouse team in collaboration with Nara University in Japan are currently preparing their new molecule-car.
Selected publications
[1] Synthesis of technomimetic molecules : Towards rotation control in single molecular machines and motors
G. Rapenne, Org. Biomol. Chem. 2005, 3, 1165-1169. Download
[2] Rolling single “nano-wheels” with the STM tip
L. Grill, X. Bouju, G. Rapenne, S. Stojkovic, C. Joachim, K.-H. Rieder, F. Moresco, Nature Nanotech.2007, 2, 95-98. Download
[3] Molecular Machines : Synthesis and characterization of two prototypes of molecular wheelbarrows
G. Rapenne, G. Jimenez-Bueno, Tetrahedron2007, 63, 7018-7026. Download
[4] Synthesis of polycyclic aromatic hydrocarbon-based nanovehicles equiped with triptycene wheels.
H.P. Jacquot de Rouville, R. Garbage, R.E. Cook, A.R. Pujol, A.M. Sirven, G. Rapenne, Chem. Eur. J.2012, 18,3023-3031. Download
[5] Synthesis and STM-imaging of symmetric and dissymmetric ethynyl-bridged dimers of boron-subphthalocyanine bowl-shaped nano-wheels.
H.P. Jacquot de Rouville, R. Garbage, F. Ample, A. Nickel, J. Meyer, F. Moresco, C. Joachim, G. Rapenne, Chem. Eur. J.2012, 18, 8925-8928. Download
[6] Molecule concept-nanocars : chassis, wheels and motors ?
C. Joachim, G. Rapenne, ACS Nano, 2013, 7, 11-14. Download
[7] Surface manipulation of a curved polycyclic aromatic hydrocarbon-based nano-vehicle molecule equipped with triptycene wheels
W.-H. Soe, C. Durand, O. Guillermet, S. Gauthier, H.-P. Jacquot de Rouville, S. Srivastava, C. Kammerer, G. Rapenne, C. Joachim, Nanotechnology 2018, 7, 495401. Download
Fundings
CNRS, EU, ANR, IUF, Université de Toulouse.
