title: Tribromobenzene on Cu(111): Temperature-dependent formation of halogen-bonded, organometallic, and covalent nanostructures.
abstract: The temperature-controlled surface-assisted synthesis of halogen bonded, organometallic, and covalent nanostructures based on 1,3,5-tribromo-benzene (TriBB) was studied with scanning tunneling microscopy and X-ray photoemission spectroscopy in ultrahigh vacuum. Vapor deposition of TriBB onto a Cu(111) surface held at 90 K leads to the formation of large domains of a honeycomb-like organic monolayer structure stabilized by triangular nodes with Br⋯Br intermolecular bonds. Upon annealing the organic monolayer to ∼140 K, a new hexagonal close-packed structure with intact TriBB molecules connected by Cu adatoms is formed. Further warming up the sample to 300 K gives rise to the scission of C-Br bonds and formation of C-Cu-C bonds between phenyl fragments such that stable dendritic organometallic networks are formed. Larger islands of organometallic networks are obtained by maintaining the temperature of Cu(111) at 420 K during deposition of TriBB. Simultaneously, large islands of Br atoms are formed around the organometallic networks. Annealing the more extended organometallic network (prepared at 420 K) to 520 K leads to the formation of a branched covalent organic framework (COF) which comprises structural elements of porous graphene and is surrounded by Br islands. These organometallic networks and COFs appear as small dendritic and branched domains, most likely due to the steric influence exerted by the Br islands.
authors.affiliation: National Synchrotron Radiation Laboratory and Collaborative Innovation Center of Suzhou Nano Science and Technology, University of Science and Technology of China, Hefei 230029, People's Republic of China.
authors.forename: Qitang
authors.initials: Q
authors.lastname: Fan
authors.affiliation: National Synchrotron Radiation Laboratory and Collaborative Innovation Center of Suzhou Nano Science and Technology, University of Science and Technology of China, Hefei 230029, People's Republic of China.
authors.forename: Tao
authors.initials: T
authors.lastname: Wang
authors.affiliation: Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026,People's Republic of China.
authors.forename: Liming
authors.initials: L
authors.lastname: Liu
authors.affiliation: Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026,People's Republic of China.
authors.forename: Jin
authors.initials: J
authors.lastname: Zhao
authors.affiliation: National Synchrotron Radiation Laboratory and Collaborative Innovation Center of Suzhou Nano Science and Technology, University of Science and Technology of China, Hefei 230029, People's Republic of China.
authors.forename: Junfa
authors.initials: J
authors.lastname: Zhu
authors.affiliation: Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Str. 4, 35032 Marburg, Germany.
authors.forename: J Michael
authors.initials: JM
authors.lastname: Gottfried