title: Pasteur's Experiment Performed at the Nanoscale: Manual Separation of Chiral Molecules, One by One.
abstract: Understanding the principles of molecular recognition is a difficult task and calls for investigation of appropriate model systems. Using the manipulation capabilities of scanning tunneling microscopy (STM) we analyzed the chiral recognition in self-assembled dimers of helical hydrocarbons at the single molecule level. After manual separation of the two molecules of a dimer with a molecule-terminated STM tip on a Cu(111) surface, their handedness was subsequently determined with a metal atom-terminated tip. We find that these molecules strongly prefer to form heterochiral pairs. Our study shows that single molecule manipulation is a valuable tool to understand intermolecular recognition at surfaces.
authors.affiliation: †Nanoscale Materials Science, Empa, Swiss Federal Laboratories for Materials Testing and Research, Überlandstrasse 129, CH-8600 Dübendorf, Switzerland.|‡IBM Almaden Research Center, 650 Harry Road, San Jose, California-95120, United States.|§Department of Chemistry, University of Zurich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland.
authors.forename: Karl-Heinz
authors.initials: KH
authors.lastname: Ernst
authors.affiliation: ‡IBM Almaden Research Center, 650 Harry Road, San Jose, California-95120, United States.|∥Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056 Basel, Switzerland.
authors.forename: Susanne
authors.initials: S
authors.lastname: Baumann
authors.affiliation: ‡IBM Almaden Research Center, 650 Harry Road, San Jose, California-95120, United States.
authors.forename: Christopher P
authors.initials: CP
authors.lastname: Lutz
authors.affiliation: †Nanoscale Materials Science, Empa, Swiss Federal Laboratories for Materials Testing and Research, Überlandstrasse 129, CH-8600 Dübendorf, Switzerland.
authors.forename: Johannes
authors.initials: J
authors.lastname: Seibel
authors.affiliation: §Department of Chemistry, University of Zurich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland.
authors.forename: Laura
authors.initials: L
authors.lastname: Zoppi
authors.affiliation: ‡IBM Almaden Research Center, 650 Harry Road, San Jose, California-95120, United States.
authors.forename: Andreas J
authors.initials: AJ
authors.lastname: Heinrich
keywords: STM; Single molecule manipulation; chirality; intermolecular recognition