Regensburg 2007 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 41: Metal Substrates: Adsorption II
O 41.1: Vortrag
Mittwoch, 28. März 2007, 15:45–16:00, H39
Controllable molecular registration state in self-assembly of 3(5)-(9-anthryl) pyrazole molecule on Ag(111) — •Ruifen Dou1, Arno Tilkorn1, Dingyong Zhong1, Wenchong Wang1, Yue Wang2, Lifeng Chi1, and Harald Fuchs1 — 1Physikalisches Institut, Universitaet Muenster, 48149 Muenster, Germany — 2Key Laboratory for Supramolecular Structure and Materials of Ministry of Education, Jilin University, Changchun 130012, China
The highly-ordered molecular structures of 3(5)-(9-anthryl) pyrazole (ANP) have been investigated on Ag(111) by low-energy electron diffraction (LEED) and scanning tunneling microscopy (STM). Through tailoring film preparation, two different superstructures, α and β, corresponding to two different molecular registration states have been obtained on Ag(111). At the low substrate temperature (229 K), the structure α can be prepared, in which the ANP molecule is adsorbed the surface with the anthryl-group plane tilting in respect to the substrate surface. After annealing the sample to room temperature, it is found that the structure α gradually evolves into the structure β with four molecules bound together through the hydrogen bonds among them and the anthryl-group plane parallel to the substrate surface to compromise to forming hydrogen bonds. Our analysis reveals a fact that the adsorbate-substrate interaction dominated in the structure α can change into the hydrogen-bonds prevailed over the structure β as mediating the growth temperature, which is responsible for the variation in the molecular registration states from the anthryl-group plane tilting with the substrate surface to parallel to surface.