title: Monitoring the reversible photoisomerization of an azobenzene-functionalized molecular triazatriangulene platform on Au(111) by IRRAS.
abstract: Spectroscopic evidence of a reversible, photoinduced trans ↔ cis photoisomerization is provided for an azobenzene-functionalized triazatriangulene (TATA) platform on Au(111). As shown by scanning tunneling microscopy (STM) and X-ray photoelectron spectroscopy (XPS), these molecules form a well-ordered self-assembled monolayer (SAM) on Au(111). The surface-adsorbed azo-TATA platforms are also investigated by infrared reflection absorption spectroscopy (IRRAS); a methoxy marker group at the upper phenyl ring of the azo moiety is employed to monitor the switching state. The IRRAS data are analyzed by comparison with theoretical and transmission IR spectra as well as bulk and surface-enhanced Raman spectroscopic (SERS) data. IRRAS shows that the methoxy group is oriented perpendicular to the surface in trans- and tilted with respect to the surface normal in cis-configuration. This indicates that the photoswitching capability of the azobenzene moieties is retained on the gold surface. The lifetime of the cis-configuration is, however, reduced by a factor of ∼10(3) with respect to the homogeneous solution.
authors.affiliation: Institut für Anorganische Chemie, Christian-Albrechts-Universität Kiel, Max-Eyth-Str. 2, 24118 Kiel, Germany. ftuczek@ac.uni-kiel.de.
authors.forename: Hanne
authors.initials: H
authors.lastname: Jacob
authors.forename: Sandra
authors.initials: S
authors.lastname: Ulrich
authors.forename: Ulrich
authors.initials: U
authors.lastname: Jung
authors.forename: Sonja
authors.initials: S
authors.lastname: Lemke
authors.forename: Talina
authors.initials: T
authors.lastname: Rusch
authors.forename: Christian
authors.initials: C
authors.lastname: Schütt
authors.forename: Finn
authors.initials: F
authors.lastname: Petersen
authors.forename: Thomas
authors.initials: T
authors.lastname: Strunskus
authors.forename: Olaf
authors.initials: O
authors.lastname: Magnussen
authors.forename: Rainer
authors.initials: R
authors.lastname: Herges
authors.forename: Felix
authors.initials: F
authors.lastname: Tuczek