title: Solvent induced polymorphism in supramolecular 1,3,5-benzenetribenzoic acid monolayers.
abstract: This work presents a scanning tunneling microscopy (STM) based study of benzenetribenzoic acid (BTB) monolayer structures at the liquid-solid interface. On graphite(0001) the tailored molecules self-assemble into 2D supramolecular host systems, suitable for the incorporation of other nanoscopic objects. Two crystallographically different BTB structures were found-both hydrogen bonded networks. A specific structure was deliberately selected by solvent identity. One of the BTB polymorphs is a 6-fold chicken-wire structure with circular, approximately 2.8 nm wide cavities. The other structure exhibits an oblique unit cell and a different hydrogen bonding pattern. The large cavity size of the chicken-wire structure was made possible through comparatively strong 2-fold hydrogen bonds between carboxylic groups. In addition, the low conformational flexibility of BTB was supportive to combat the tendency for dense packing.
authors.affiliation: Department für Geo- und Umweltwissenschaften, Ludwig Maximilians Universität München and Center for Nanoscience, Theresienstrasse 41, D-80333 München, Germany.
authors.forename: Lorenz
authors.initials: L
authors.lastname: Kampschulte
authors.forename: Markus
authors.initials: M
authors.lastname: Lackinger
authors.forename: Anne-Kathrin
authors.initials: AK
authors.lastname: Maier
authors.forename: Ravuri S K
authors.initials: RS
authors.lastname: Kishore
authors.forename: Stefan
authors.initials: S
authors.lastname: Griessl
authors.forename: Michael
authors.initials: M
authors.lastname: Schmittel
authors.forename: Wolfgang M
authors.initials: WM
authors.lastname: Heckl