Speaker
Description
Artificial molecular motors are fundamental components of nanoscale machines that convert external energy into uni-directional motion. On metallic surfaces, their operation can be probed with sub-molecular precision, allowing observation of rotational pathways and intermediates.
In nanomachines, it could be advantageous to have not only one, but several motor units incorporated. However, the synthesis of such complex molecules is very challenging. Here, we studied whether individual Feringa-type motor units can be coupled covalently directly on a Au(111) surface to form bimotors, thus avoiding the complex synthesis and difficult deposition of molecules that contain more than one motor unit. Using low-temperature scanning tunnelling microscopy (STM) under ultrahigh vacuum conditions, we identified individual bimotor molecules after the coupling and could resolve distinct conformations. Moreover, conformational transitions and lateral translation could be induced by STM tip manipulation. In addition to discrete bimotor formation, we also observed chain growth of molecular motors on Au(111) from a different monomotor precursor.
Our results demonstrate controlled reactions and manipulation of molecular motors on a metallic surface, supporting the development of more complex nanomachines.