title: Molecules with multiple switching units on a Au(111) surface: self-organization and single-molecule manipulation.
abstract: Three different molecules, each containing two azobenzene switching units, were synthesized, successfully deposited onto a Au(111) surface by sublimation and studied by scanning tunneling microscopy at low temperatures. To investigate the influence of electronic coupling between the switching units as well as to the surface, the two azo moieties were connected either via π-conjugated para-phenylene or decoupling meta-phenylene bridges, and the number of tert-butyl groups was varied in the meta-phenylene-linked derivatives. Single molecules were found to be intact after deposition as identified by their characteristic appearance in STM images. Due to their mobility on the Au(111) surface at room temperature, the molecules spontaneously formed self-organized molecular arrangements that reflected their chemical structure. While lateral displacement of the molecules was accomplished by manipulation, trans-cis isomerization processes, typical for azobenzene switches, could not be induced.
authors.affiliation: Department of Physical Chemistry, Fritz-Haber-Institute of the Max-Planck-Society, D-14195 Berlin, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Mielke
authors.forename: Sofia
authors.initials: S
authors.lastname: Selvanathan
authors.forename: Maike
authors.initials: M
authors.lastname: Peters
authors.forename: Jutta
authors.initials: J
authors.lastname: Schwarz
authors.forename: Stefan
authors.initials: S
authors.lastname: Hecht
authors.forename: Leonhard
authors.initials: L
authors.lastname: Grill