title: Control of intermolecular bonds by deposition rates at room temperature: hydrogen bonds versus metal coordination in trinitrile monolayers.
abstract: Self-assembled monolayers of 1,3,5-tris(4'-biphenyl-4"-carbonitrile)benzene, a large functional trinitrile molecule, on the (111) surfaces of copper and silver under ultrahigh vacuum conditions were studied by scanning tunneling microscopy and low-energy electron diffraction. A densely packed hydrogen-bonded polymorph was equally observed on both surfaces. Additionally, deposition onto Cu(111) yielded a well-ordered metal-coordinated porous polymorph that coexisted with the hydrogen-bonded structure. The required coordination centers were supplied by the adatom gas of the Cu(111) surface. On Ag(111), however, the well-ordered metal-coordinated network was not observed. Differences between the adatom reactivities on copper and silver and the resulting bond strengths of the respective coordination bonds are held responsible for this substrate dependence. By utilizing ultralow deposition rates, we demonstrate that on Cu(111) the adatom kinetics plays a decisive role in the expression of intermolecular bonds and hence structure selection.
authors.affiliation: Department of Physics, Technische Universität München, James-Franck-Str. 1, 85748 Garching, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Sirtl
authors.forename: Stefan
authors.initials: S
authors.lastname: Schlögl
authors.forename: Atena
authors.initials: A
authors.lastname: Rastgoo-Lahrood
authors.forename: Jelena
authors.initials: J
authors.lastname: Jelic
authors.forename: Subhadip
authors.initials: S
authors.lastname: Neogi
authors.forename: Michael
authors.initials: M
authors.lastname: Schmittel
authors.forename: Wolfgang M
authors.initials: WM
authors.lastname: Heckl
authors.forename: Karsten
authors.initials: K
authors.lastname: Reuter
authors.forename: Markus
authors.initials: M
authors.lastname: Lackinger