Dresden 2011 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
O: Fachverband Oberflächenphysik
O 19: Metal substrates: Adsorption of O / H and inorganic molecules II
O 19.2: Vortrag
Montag, 14. März 2011, 17:30–17:45, WIL A317
The influence of monomer size on reaction kinetics and defect density for the synthesis of 2D Covalent Organic Frameworks: a combined Scanning-Tunneling-Microscopy and Density Functional Theory study — •Stefan Schlögl1,2, Wolfgang M. Heckl2,3, and Markus Lackinger1,2 — 1Geowissenschaftliches Institut & CeNS, LMU München — 2Deutsches Museum, München — 3School of Education, Department Physik, TU München
In order to tailor mechanical, chemical, and electronic properties of two-dimensional polymers, a bottom-up surface mediated fabrication process under controlled conditions is very promising. On one hand covalent intermolecular bonds give rise to the strength of 2D materials, on the other hand their irreversible character renders growth associated structural defects permanent. In order to control 'covalent self-assembly', a fundamental understanding of reaction kinetics and defect energetics is necessary.
In this contribution, we study and compare the surface mediated polymerization of 1,3,5-Triiodobenzene (TIB) and 1,3,5-Tris-(4-bromophenyl)benzene (TBPB). Deposition of the monomers onto dense packed metal surfaces under UHV conditions results in full dehalogenation and subsequent addition of the radicals into covalent aggregates. In this talk, we will address the fate of the split-off halogen atom, the topology of resulting covalent aggregates, the role of the organic backbone, and the influence of thermal after-treatments. The structures and energetics are analyzed and discussed by Scanning Tunneling Microscopy and Density Functional Theory calculations.