title: Photoreaction of matrix-isolated dihydroazulene-functionalized molecules on Au{111}.
abstract: Dihydroazulenes are photochromic molecules that reversibly switch between two distinct geometric and conductivity states. Molecular design, surface attachment, and precise control over the assembly of such molecular machines are critical in order to understand molecular function and motion at the nanoscale. Here, we use surface-enhanced Raman spectroscopy on special atomically flat, plasmonically enhanced substrates to measure the photoreaction kinetics of isolated dihydroazulene-functionalized molecules assembled on Au{111}, which undergo a ring-opening reaction upon illumination with UV light and switch back to the initial isomer via thermal relaxation. Photokinetic analyses reveal the high efficiency of the dihydroazulene photoreaction on solid substrates compared to other photoswitches. An order of magnitude decrease in the photoreaction cross section of surface-bound dihydroazulenes was observed when compared with the cross sections of these molecules in solution.
authors.affiliation: California NanoSystems Institute, University of California, Los Angeles, Los Angeles, California 90095, USA.
authors.forename: Bala Krishna
authors.initials: BK
authors.lastname: Pathem
authors.forename: Yue Bing
authors.initials: YB
authors.lastname: Zheng
authors.forename: Seth
authors.initials: S
authors.lastname: Morton
authors.forename: Michael Åxman
authors.initials: MÅ
authors.lastname: Petersen
authors.forename: Yuxi
authors.initials: Y
authors.lastname: Zhao
authors.forename: Choong-Heui
authors.initials: CH
authors.lastname: Chung
authors.forename: Yang
authors.initials: Y
authors.lastname: Yang
authors.forename: Lasse
authors.initials: L
authors.lastname: Jensen
authors.forename: Mogens Brøndsted
authors.initials: MB
authors.lastname: Nielsen
authors.forename: Paul S
authors.initials: PS
authors.lastname: Weiss
mesh_terms: D052176:Azulenes / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D015394:Molecular Structure; D010316:Particle Size; D055668:Photochemical Processes; D013499:Surface Properties; D014466:Ultraviolet Rays
chemical_list: D052176:Azulenes; C507545:dihydroazulene; D006046:Gold