title: Supramolecular control of two-dimensional phase behavior.
abstract: We have used directed two-component self-assembly to "pattern" organic monolayers on the nanometer scale at the liquid/solid interface. The ability of the scanning tunneling microscope to investigate structural details in these adlayers was used to gain insight into the two-component two-dimensional phase behavior. The components are symmetrically alkylated bisurea derivatives (R1-urea-spacer-urea-R2; R1, R2=alkyl, spacer=alkyl or bisthiophene). The bisthiophene unit acts as a marker and its bisurea derivative (T2) is a component in all the mixtures investigated. By varying the position of the hydrogen-bond forming urea groups along the molecule and the length of the alkyl chains of the other components, the effect of 1) hydrogen bonding, 2) molecule length, 3) odd-even effects, and 4) shape complementarity on the two-dimensional phase behavior was investigated. Insight into the effect of these parameters leads to the control of the two-dimensional patterning: from randomly intermixed systems to phase separation.
authors.affiliation: Katholieke Universiteit Leuven, Departement Scheikunde Celestijnenlaan 200 F, 3001 Leuven, Belgium. steven.defeyter@chem.kuleuven.ac.be
authors.forename: Steven
authors.initials: S
authors.lastname: De Feyter
authors.forename: Mattias
authors.initials: M
authors.lastname: Larsson
authors.forename: Norbert
authors.initials: N
authors.lastname: Schuurmans
authors.forename: Bas
authors.initials: B
authors.lastname: Verkuijl
authors.forename: George
authors.initials: G
authors.lastname: Zoriniants
authors.forename: André
authors.initials: A
authors.lastname: Gesquière
authors.forename: Mohamed M
authors.initials: MM
authors.lastname: Abdel-Mottaleb
authors.forename: Jan
authors.initials: J
authors.lastname: van Esch
authors.forename: Ben L
authors.initials: BL
authors.lastname: Feringa
authors.forename: Jan
authors.initials: J
authors.lastname: Van Stam
authors.forename: Frans
authors.initials: F
authors.lastname: De Schryver