Fan Qitang, Wang Tao, Liu Liming, Zhao Jin, Zhu Junfa, Gottfried J Michael
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.
Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026,People's Republic of China.
J Chem Phys. 2015 Mar 14;142(10):101906. doi: 10.1063/1.4906214.
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.
在超高真空环境下，利用扫描隧道显微镜和X射线光电子能谱对基于1,3,5 - 三溴苯（TriBB）的卤素键合、有机金属和共价纳米结构的温控表面辅助合成进行了研究。将TriBB气相沉积到保持在90 K的Cu(111)表面上，会形成由具有Br⋯Br分子间键的三角形节点稳定的蜂窝状有机单层结构的大区域。将有机单层退火至约140 K时，会形成一种新的六方密堆积结构，其中完整的TriBB分子通过Cu吸附原子相连。进一步将样品加热至300 K会导致C - Br键断裂，并在苯基片段之间形成C - Cu - C键，从而形成稳定的树枝状有机金属网络。通过在TriBB沉积过程中将Cu(111)的温度保持在420 K，可以获得更大的有机金属网络岛。同时，在有机金属网络周围会形成大的Br原子岛。将更扩展的有机金属网络（在420 K制备）退火至520 K会导致形成一种分支共价有机框架（COF），该框架包含多孔石墨烯的结构元素，并被Br岛包围。这些有机金属网络和COF表现为小的树枝状和分支区域，这很可能是由于Br岛施加的空间位阻影响。
