Science 325,1110-1114 (2009) Behold pentacene (pictured right), a five-ringed hydrocarbon molecule shown with remarkable clarity thanks to an atomic force microscope with a crucial modification.rnLeo Gross and his colleagues at IBM Research in Zurich, Switzerland, placed a carbon monoxide molecule on the tip of the microscope's sensitive detector. The tip scans over the surface and is deflected by its interaction with the atoms in the sample.rnChoosing the right molecule for the tip enabled repulsion due to the electronic exclusion principle to dominate over the blurring caused by attractive Van der Waals and electrostatic forces. The improved contrast allowed the researchers to resolve the positions of individual molecules and the bonds between them.
展开▼
