We acquired systematically time - resolved STM data of the switching events as af unction of the temperature , tunnelling bias and tunnelling current . We find that the range of tunnelling conditions employed here does not influence the switching events , s ow ec an use STM to follow the natural thermally activated rotation of the guest molecules within the nanopore ( Supporting Information Figure S10 ) . However , the possibility of tip - induced activated rotation under different tunnelling conditions exists . N oc orrelation of the rotations and positions of the neighbouring caged guests was noticed , we therefore considered them as independent rotors . W e recorded the frequencyo fr otation events by % 1208 8 as afunction of temperature ( see plot in Figure 5Aand Methods in Supporting Information ) . With an Arrhenius equation fitting , the barrier is determined to be 0.95 eV AE 0.07 eV with acorresponding pre - exponential factor of % 2.3 10 14AE1 s À1 .