Dissymmetrical U‐Shaped π‐Stacked Supramolecular Assemblies by Using a Dinuclear CuI Clip with Organophosphorus Ligands and Monotopic Fully π‐Conjugated Ligands |
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Authors: | Dr. Mehdi El Sayed Moussa Dr. Kevin Guillois Dr. Wenting Shen Prof. Régis Réau Dr. Jeanne Crassous Dr. Christophe Lescop |
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Affiliation: | Institut des Sciences Chimiques de Rennes, UMR 6226 CNRS, Université de Rennes 1, Campus de Beaulieu, 35042 Rennes Cedex (France), Fax: (+33)?2‐23‐23‐69‐39 |
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Abstract: | ![]() Reactions between the U‐shaped binuclear CuI complex A that bears short metal–metal distances and the cyano‐capped monotopic π‐conjugated ligands 1 – 5 that carry gradually bulkier polyaromatic terminal fragments lead to the formation of π‐stacked supramolecular assemblies 6 – 10 , respectively, in yields of 50–80 %. These derivatives have been characterized by multinuclear NMR spectroscopic analysis and X‐ray diffraction studies. Their solid‐state structures show the selective formation of U‐shaped supramolecular assemblies in which two monotopic π‐conjugated systems present large ( 6 , 7 , and 9 ) or medium ( 8 and 10 ) intramolecular π overlap, thus revealing π–π interactions. These assemblies self‐organize into head‐to‐tail π‐stacked dimers that in turn self‐assemble to afford infinite columnar π stacks. The nature, extent, and complexity of the intermolecular contacts within the head‐to‐tail π‐stacked dimer depend on the nature of the terminal polyaromatic fragment carried by the cyano‐capped monotopic ligand, but it does not alter the result of the self‐assembling process. These results demonstrate that the dinuclear molecular clip A that bears short metal–metal distances allows selective supramolecular assembly processes driven by the formation of intra‐ and intermolecular short π–π interactions in the resulting self‐assembled structures; thus, demonstrating that their shape is not only dictated by the symmetry of the building blocks. This approach opens perspectives toward the formation of extended π‐stacked columns based on dissymmetrical and functional π‐conjugated systems. |
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Keywords: | conjugation noncovalent interactions P ligands polycycles self‐assembly |
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