STM investigation of flexible supramolecules: benzylic amide [2] catenanes

Benzylic amide [2] catenane (CAT1) deposited from a methanol solution onto highly oriented pyrolitic graphite (HOPG) has been investigated by ambient scanning tunneling microscopy (STM). Submolecular features are resolved which suggest that the adsorption of CAT1 is driven by the electrostatic attraction of carbonyl groups and HOPG. Our evidence shows that CAT1 is mobile at RT on HOPG surface. A statistical analysis of the observed features reveals a bimodal distribution of the lateral size which correlates with the expected diameter of a single macrocycle and the catenane respectively.