Single molecule thermal gearing effect

Observation of a thermally activated gearing effect between two hexa- tert -butyl-decacyclene (HBDC) molecule-gears is reported using the Au(111) surface to constrain lateral diffusion of the molecules at 77 K. An on-purpose selected small 2D HBDC nano-island is first destabilized using the tip of a scanning tunneling microscope (STM) in a soft-pulling mode of molecular manipulation. It follows a long sequence of thermally activated spontaneous molecular reconfigurations, leading up to a molecular gearing effect. Using coupled Langevin equations, a simulation of this thermal process is proposed to determine the conditions for this thermally activated gearing effect. • Soft rotational mechanical manipulation of a single molecule with STM-tip at LN 2 . • Thermally activated gearing effect between two HBDC molecules on an surface. • Dynamic analysis of thermal gearing using coupled Langevin equations.