Diels-Alder attachment of a planar organic molecule to a dangling bond dimer on a hydrogenated semiconductor surface.
Construction of single-molecule electronic devices requires the controlled manipulation of organic molecules and their properties. This could be achieved by tuning the interaction between the molecule and individual atoms by local "on-surface" chemistry, i.e., the controlled formation of chemical bonds between the species. We demonstrate here the reversible attachment of a planar conjugated polyaromatic molecule to a pair of unpassivated dangling bonds on a hydrogenated Ge(001):H surface via a Diels-Alder [4+2] addition using the tip of a scanning tunneling microscope (STM). Due to the small stability difference between the covalently bonded and a nearly undistorted structure attached to the dangling bond dimer by long-range dispersive forces, we show that at cryogenic temperatures the molecule can be switched between both configurations. The reversibility of this covalent bond forming reaction may be applied in the construction of complex circuits containing organic molecules with tunable properties.
Centre for Nanometer-Scale Science and Advanced Materials, NANOSAM, Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, Lojasiewicza 11, PL 30-348, Krakow, Poland. szymon.godlewski@uj.edu.pl.
Szymon
S
Godlewski
Institute of Materials Research and Engineering, 2 Fusionopolis Way, Innovis, #08-03, Singapore 138634, Singapore. kawaih@imre.a-star.edu.sg.
Hiroyo
H
Kawai
Centro de Fisica de Materiales CSIC-UPV/EHU, Paseo Manual de Lardizabal 5, E-20018, Donostia-San Sebastian, Spain.
Mads
M
Engelund
Centre for Nanometer-Scale Science and Advanced Materials, NANOSAM, Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, Lojasiewicza 11, PL 30-348, Krakow, Poland. szymon.godlewski@uj.edu.pl.
Marek
M
Kolmer
Centre for Nanometer-Scale Science and Advanced Materials, NANOSAM, Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, Lojasiewicza 11, PL 30-348, Krakow, Poland. szymon.godlewski@uj.edu.pl.
Rafal
R
Zuzak
Donostia International Physics Center, Paseo Manual de Lardizabal 4, 20018, Donostia-San Sebastian, Spain and IKERBASQUE, Basque Foundation for Science, E-48013, Bilbao, Spain.
Aran
A
Garcia-Lekue
Laboratory for Chemical Technology, Ghent University, Technologiepark 914, 9052 Ghent, Belgium.
Gerard
G
Novell-Leruth
Institute of Chemical Research of Catalonia (ICIQ), Avenida Països Catalans 16, 43007 Tarragona, Spain.
Antonio M
AM
Echavarren
Centro de Fisica de Materiales CSIC-UPV/EHU, Paseo Manual de Lardizabal 5, E-20018, Donostia-San Sebastian, Spain and Donostia International Physics Center, Paseo Manual de Lardizabal 4, 20018, Donostia-San Sebastian, Spain.
Daniel
D
Sanchez-Portal
Nanosciences Group & MANA Satellite, CEMES-CNRS, 29 rue Jeanne Marvig, F-31055 Toulouse, France and International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.
Christian
C
Joachim
Laboratory for Chemical Technology, Ghent University, Technologiepark 914, 9052 Ghent, Belgium.
Mark
M
Saeys