Regensburg 2013 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
O: Fachverband Oberflächenphysik
O 42: Organic/bio Molecules on Metal Surfaces IV
O 42.9: Talk
Wednesday, March 13, 2013, 12:30–12:45, H38
Synthesis of 2D covalent networks through Ullmann coupling of a threefold symmetric hexabrominated molecule — •Atena Rastgoo Lahrood1,2, Thomas Sirtl1,2, Wolfgang Heckl1,2, and Markus Lackinger1,2 — 1Department of Physics & TUM School of Education, Tech. Univ. Munich, Schellingstrasse 33, 80333 Munich, Germany — 2Deutsches Museum, Museumsinsel 1, 80538 Munich, Germany
Over the last few years, 2D covalent materials have gained a lot of interest in different fields of studies because of their extraordinary properties. One of the common bottom-up synthesis methods for 2D covalent networks is surface mediated polymerization of halogenated organic monomers. Thereby, surface stabilized radicals are generated through the homolysis of carbon-halogen bonds. Subsequent diffusion and radical recombination reactions yield covalently cross-linked networks. In this contribution we will discuss the role of the monomer halogen substitution pattern for the topology and defect density in covalent networks. Moreover, comparative studies on densely packed coinage metal surfaces (Cu(111), Ag(111), Au(111)) and additional thermal treatment reveal the influence of further important parameters. The structures are prepared in ultra-high vacuum and analyzed by STM and LEED. Molecules were also deposited onto Ag(111) and Cu(111) at low temperature and structural changes that hint toward the onset of polymerization were studied as a function of temperature.