Raising flags: Applications of chemical marker groups to study self- assembly, chirality, and orientation of interfacial films by scanning tunneling

Abstract

When used in conjunction with 'chemical marker groups' (functionalities such as - Br and - COOH), scanning tunneling microscopy is a powerful tool for studying the properties of liquid - solid interfaces. Chemical markers serve as 'flags' for the identification of interfacial structures, allowing, for example, the absolute chirality of optically active molecules self- assembling on a graphite surface to be determined. Subtle changes in the orientation of these chemical functionalities that affect the long-range order of interfacial films have also been observed and explored. Finally, alterations in self-assembly resulting from variations in adsorbate or substrate structure can be deduced by taking advantage of these STM 'flags'.