Centre d’Élaboration de Matériaux et d’Etudes Structurales (UPR 8011)

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Molecular motors

Goal : convert an electron flux in a unidirectional rotation

Staff: Claire Kammerer (Ass. Prof.), Gwénaël Rapenne (Prof.), Jean-Pierre Launay (Emeritus Prof.), Christian Joachim (CNRS Research Director)
Ph.D. students & Postdocs: J. Echeverria (Post-doc), A. Sirven (PhD 2012-15), J.P.D.C. Calupitan (PhD 2015-18), Y. Gisbert (PhD 2018-21), R. Asato (PhD 2018-21)

In the field of nanoscience in general and molecular nanomechanics in particular, one of the challenges is the design and construction of a nanoscale molecular motor. It is a machine that continuously transforms energy by producing a work through controlled unidirectional rotation. The motors that we have synthesized have been designed to be addressed individually.

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A molecular motor schematized in between two nanoelectrodes

We have synthesized several molecules of different size and chemical constitution, illustrating the various criteria that should be met. First of all, the system should be as rigid as possible so as to avoid useless rotations that would waste energy in unwanted movements. Then, the rotation should be easy around the vertical axis but not at the expense of the integrity of the molecule, i.e. dissociation of the fixed and mobile parts should be prevented.

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Molecular motors synthesized in our laboratory. Platinum and bicyclo[2,2,2]octane fragments are insulating spacers to minimize the intramolecular electron transfers.

In collaboration with Prof. Saw-Wai Hla (Ohio University), we studied this electro-induced rotation. By placing the molecule at a temperature of 5K on the gold surface, we managed to trigger the rotor’s stepwise movement and to control the direction of rotation. For this, we use electrons from the tip of a tunneling microscope that serves as both an observation instrument and a source of energy. As shown in the figure below, the direction of rotation depends on the rotor blade where the tip of the microscope tip is positioned.

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The “molecular motor” is anchored to the surface via three attachment points. The upper platform turns in either direction around its axis, depending on the position of the tip of the microscope.
© G. Rapenne and G. Vives, CEMES, CNRS/UPS

A few years later, we developed a new family of molecular motors that are designed to work synchronously at higher temperatures. Ferroelectric behavior was demonstrated in a self-assembled monolayer on a gold surface with synchronized rotation under the influence of the electric field induced by the STM tip. This rotation occurs over long distances, only limited by the ends of the domains of the surface.

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Selected publications

[1] Controlled clockwise and anticlockwise rotational switching of a molecular motor
U.G.E. Perera, F. Ample, H. Kersell, Y. Zhang, J. Echeverria, M. Grisolia, G. Vives, G. Rapenne, C. Joachim, S.W. Hla, Nature Nanotech. 2013, 8, 46-51. Download

[2] Scorpionate hydrotris(indazolyl)borate ligands as tripodal platform for surface-mounted molecular motors and gears
C. Kammerer, G. Rapenne, Eur. J. Inorg. Chem. 2016, 2214-2216. Download 

[3] Controlled directional motions of molecular vehicles, rotors and motors: from metallic to silicon surfaces, a strategy to operate at higher temperature
F. Chérioux, F. Palmino, O. Galangau, G. Rapenne, Chem. Phys. Chem. 2016, 1742-1751. Download

[4]  Simultaneous and coordinated rotational switching of all molecular rotors in a network
Y. Zhang, H. Kersell, R. Stefak, J. Echeverria, V. Iancu, G. Perera, Y. Li, A. Deshpande, K.-F. Braun, C. Joachim, G. Rapenne, S.-W. Hla, Nature Nanotech. 2016, 11, 706-713. Download

[5] De la miniaturisation des machines à la construction de moteurs moléculaires
A.M. Sirven, C. Kammerer, G. Rapenne, Act. Chim. 2017, 418, 17-24. Download

[6] Expedient synthesis of thioether-functionalized hydrotris(indazolyl) borate as an anchoring platform for rotary molecular machines
G. Erbland, Y. Gisbert, G. Rapenne, C. Kammerer, Eur. J. Org. Chem 2018, 4731-4739. Download

[7] Biomimetic and technomimetic single molecular machines
C. Kammerer, G. Erbland, Y. Gisbert, T. Nishino, K. Yasuhara, G. Rapenne, Chem. Lett. 2019, 48, 299-308. Download Couverture

[8] A chiral molecular propeller designed for unidirectional rotations on a surface Y. Zhang, J.P. Calupitan, T. Rojas, R. Tumbleson, G. Erbland, C. Kammerer, T.M. Ajayi, S. Wang, L.C. Curtiss, A.T. Ngo, S.E. Ulloa, G. Rapenne, S.W. Hla, Nature Commun. 2019, 10, 3742. Download