Textbook images of a Molecule

Abstract

single molecules can enable or facilitate studies of various basic chemical and physical processes such as chemical reactions, charge transfer, conformational changes, and molecular adsorption on the level of individual molecules. Application in the fields of surface catalysis, organic photovoltaics, and future molecular electronic devices will benefit from such investigations. Scanning probe methods are ideally suited for investigations of individual adsorbates, in contrast to diffraction methods which only yield information for ensembles of atoms or molecules. e scanning probe methods that achieve the highest spatial resolution are scanning tunneling microscopy (STM) and its offspring, atomic force microscopy (AFM). Both methods have been successfully employed in the past to image numerous surfaces with atomic resolution, but the atomic structure of an individual molecule has not been resolved until now. To understand the particular difficulties in the imaging of molecules, it is important to review the working principles of STM and AFM.