Dresden 2014 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 49: Surface Chemical Reactions and Heterogeneous Catalysis III
O 49.5: Vortrag
Mittwoch, 2. April 2014, 11:30–11:45, PHY C 213
On-Surface Azide-Alkyne Cycloaddition on Au(111) — •Oscar Díaz Arado1, Harry Mönig1, Hendrik Wagner2, Jörn-Holger Franke1, Gernot Langewisch1, Philipp Held2, Armido Studer2, and Harald Fuchs1 — 1Physikalisches Institut and Center for Nanotechnology, WWU, Münster, Germany — 2Organisch-Chemisches Institut, WWU, Münster, Germany
Two dimensional chemical reactions have been an uprising field of research in the recent years to obtain new polymeric networks directly at surfaces under ultrahigh vacuum (UHV) conditions [1,2]. Here we present the successful cycloaddition reaction between azides and alkynes on a Au(111) surface at room temperature and under UHV conditions [3]. High-resolution scanning tunneling microscopy images reveal that these on-surface cycloadditions occur highly regioselectively to form the corresponding 1,4-triazoles. Density functional theory simulations confirm that the reactions can occur at room temperature, where the Au(111) surface does not participate as a catalytic agent in alkyne C-H activation but acts solely as a two-dimensional constraint for the positioning of the two reacting moieties. Our results provide new insights about the necessity of copper catalysts for on-surface azide-alkyne "click" chemistry. The on-surface azide-alkyne cycloaddition has great potential for the development and fabrication of functional organic nanomaterials on surfaces.
[1] D. F. Perepichka, F. Rosei, Science 2009, 323, 216 [2] L. Grill et.al., Nature Chemistry, 2012, 4 (3), pp. 215-220 [3] O. Díaz Arado et.al., ACS Nano, 2013, 7 (10), pp. 8509-8515