Strategies for the formation of covalently bonded nano- networks on metal surfaces through amine reactions.
Lee, Hooi Ling (2012) Strategies for the formation of covalently bonded nano- networks on metal surfaces through amine reactions. PhD thesis, Dublin City University.
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Recently, there has been increasing interest in the development of covalent surface supported polymeric networks. This is attributed to the fact that they are thermally, mechanically and chemically more stable than those based on hydrogen bonded or metalorganic
frameworks. The formation and characterization of organic nano-networks on metal surfaces is important for applications such as gas sensors, catalysis and molecular
templates. In this thesis, strategies for the formation of covalent networks of 5,10,15,20- tetrakis(4 aminophenyl)-porphyrin (TAPP) and 1,3,5 tris(4aminophenyl)benzene (TAPB), both of which have amine groups that are attached to phenyl rings, were extensively
investigated on Au(111), Ag(111) and Cu(111) surfaces. The strategies employed to form covalently bonded networks are based on reactions between the amine groups on the TAPP
or TAPB molecules. An investigation of the self-assembly of these molecules, deposited at room temperature, on different metal surfaces was carried out to investigate the effect of intermolecular and molecule-surface interactions. The surface elevated at different temperature was employed to investigate the formation of networks through the
polymerization of these molecules at various substrate temperatures. Polymerisation of the TAPP molecules is expected to form networks with a four-fold symmetry networks
whereas the reaction among TAPB molecules would gave three-fold symmetry networks. Further investigations were carried out on a polyimidisation reaction between the amine
molecules and the anhydride groups present on 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA). All samples were studied in detail using scanning tunneling
microcopy (STM) and X-ray photoelectron spectroscopy (XPS) measurements to investigate the structural and chemical properties of the networks. In addition, ultraviolet
photoelectron spectroscopy (UPS) and synchrotron based techniques were utilized in some of these studies. The ordering observed in the resulting structure is largely determined by the initial molecular coverage, substrate temperature, type of single crystal used and the
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