Conformational Analysis of Nonplanar Archipelago Structures on a Cu (111) Surface by Molecular Imaging

We investigated some specially designed model compounds as proxies for archipelago structures in asphaltenes and heavy oils using noncontact atomic force microscopy (nc-AFM). Various adsorption conformations of three different kinds of linkers including aryl-aryl, aryl-CH2-aryl, and aryl-(CH2)3-aryl were identified. By focusing on the nature of linkages or bridges between aromatic cores, this work directly addresses the long-standing question on petroleum molecular structures by validating detailed features in images and overcoming challenges of nonplanar structures and conformations, providing a foundation to apply nc-AFM to unknown structures in petroleum.