Perchlorination of Coronene Enhances its Propensity for Self‐Assembly on Graphene |
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Authors: | Dr Artur Ciesielski Jürgen Weippert Dr Artur Böttcher Yuyoung Shin Georgian Melinte Prof?Dr Ovidiu Ersen Dr Cinzia Casiraghi Prof?Dr Xinliang Feng Prof?Dr Klaus Müllen Prof?Dr Manfred M Kappes Prof?Dr Paolo Samorì Dr Marco Cecchini |
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Institution: | 1. Nanochemistry Laboratory, ISIS & icFRC, Université de Strasbourg & CNRS, Strasbourg (France;2. Institute of Physical Chemistry, Karlsruhe Institute of Technology (KIT), Karlsruhe (Germany;3. School of Chemistry, University of Manchester, Manchester;4. Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), UMR 7504, Strasbourg (France;5. Max Plank Institute for Polymer Research, Mainz (Germany;6. Center for Advancing Electronics Dresden (CFAED) & Department of Chemistry and Food Chemistry, Technische Universitaet Dresden, Dresden (Germany;7. Laboratoire d'Ingénierie des Fonctions Moléculaires, ISIS & icFRC, Université de Strasbourg & CNRS, Strasbourg (France |
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Abstract: | Providing a quantitative understanding of the thermodynamics involved in molecular adsorption and self‐assembly at a nanostructured carbon material is of fundamental importance and finds outstanding applications in the graphene era. Here, we study the effect of edge perchlorination of coronene, which is a prototypical polyaromatic hydrocarbon, on the binding affinity for the basal planes of graphite. First, by comparing the desorption barrier of hydrogenated versus perchlorinated coronene measured by temperature‐programmed desorption, we quantify the enhancement of the strength of physisorption at the single‐molecule level though chlorine substitution. Then, by a thermodynamic analysis of the corresponding monolayers based on force‐field calculations and statistical mechanics, we show that perchlorination decreases the free energy of self‐assembly, not only enthalpically (by enhancing the strength of surface binding), but also entropically (by decreasing the surface concentration). The functional advantage of a chemically modulated 2D self‐assembly is demonstrated in the context of the molecule‐assisted liquid‐phase exfoliation of graphite into graphene. |
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Keywords: | graphene interfaces polycyclic aromatic hydrocarbons self-assembly statistical thermodynamics |
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