Rolling a single molecular wheel at the atomic scale

[nanoorg]

Researchers from CEMES-CNRS Toulouse, France and Freie Universität Berlin, Germany, achieved for the first time to control rolling of a single molecule equipped with two wheels (0.8 nm in diameter) induced by the Scanning Tunneling Microscope tip.

Bottom-up assembly of complex molecular machines is one the main goal of nanotechnologies. French and German researchers reached a new stage to achieve this goal with a new approach of controlling the intramolecular mechanics.

This collaborative team has already experimented molecular machines. After observation of the ramdom rotation of a molecular wheel in 1998, synthesis of an unimolecular wheelbarrow in 2003 and synthesis of a molecular motor in 2005, the team achieved the control of a molecular wheel rotation.

They showed that a molecular wheel assembled on an axle can roll controling its rotation direction.

The molecular machine is compound of two triptycene wheels (0.8nm in diameter) linked to a molecular axle of 0.6nm. Molecular machine is placed on a copper surface and observed with a scanning tunneling microscope. Molecules that are on the same orientation than copper atoms lines are pushed by STM tip and begin to roll.

STM follows and records molecular machine movements to allow researchers to understand well known macroscopic functionalities at a molecular scale.

This work was published online on Nature Nanotechnology (January 21st).




Further information sources :

http://www2.cnrs.fr/presse/communique/1012.htm

http://www.nature.com/






Story first posted: 24th January 2007.