The Chemical Structure of a Molecule Resolved by Atomic Force Microscopy

Abstract

Atomic Imaging Within Adsorbed Molecules: Scanning tunneling microscopy provides atomic resolution images of surfaces and adsorbed atoms, but imaging atoms within an organic molecule adsorbed on a surface is difficult because contrast is lacking in the states that determine the tunneling current. Atomic force microscopy should be able to resolve atoms through changes in short-range chemical forces, but resolution is lost if the scanning tip undergoes modifications or if it moves the molecule. Gross et al. (p. 1110 ) show that in situ functionalization of the tip—for example, with CO—can dramatically improve the resolution of images of pentacene molecules adsorbed on conducting surfaces, like copper, and nonconductors, like NaCl.