Insights About the Mechanism of the Formation of Supramolecular π‐Stacked Rectangles Based on CuI Bimetallic Complexes Bearing a Bridging Phosphane Ligand

Abstract

AbstractThe variation in the ratio of the reactants in the supramolecular self‐assembly reaction of the bimetallic CuI “U‐shaped” molecular clip 1 with the 1,4‐dicyanobenzene 3 and the 1,8‐anthracene‐9,10‐carbonitrile 4 “short” ditopic ligand have allowed the observation of new “open” supramolecular assemblies 7 and 8, respectively, in addition to the previously characterized π‐stacked supramolecular rectangles 5 and 6, respectively. These new derivatives have been characterized by their solid‐state structure obtained by X‐ray diffraction on single crystals and by NMR spectroscopy in the case of derivative 7. Depending on the extent of the π system included in the core of the homoditopic linker, different behaviors are observed. In the case of derivative 7 based on the “phenyl” linker 3, a 1:1 1/3 ratio affords the open derivative in a good yield, whereas a 1:0.5 1/4 ratio allows the isolation of derivative 8 in very low yield. These results allow for a tentative analysis of the mechanism that occurs along with the supramolecular self‐assembly processes to afford π‐stacked supramolecular rectangles.