Supramolecular Aggregation of Perfluoroorganyl Iodane Reagents in the Solid State and in Solution

Antonio Togni; Phil Liebing; Ewa Pietrasiak; Elisabeth Otth; Jorna Kalim; Dustin Bornemann

Index: 10.1002/ejoc.201800358

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Abstract

The crystal structures of different perfluoroorganyl iodanes are described, including four new benziodoxole derivatives with RF = nC3F7, nC4F7, nC8F17 and C6F5. In all compounds, the iodine atom shows significant Lewis acidity, and the fourth coordination site is readily filled by secondary bonding interactions, giving rise to a square‐planar coordination. While the latter is a good model for benziodoxoles, benziodoxolone derivatives tend to further aggregation by additional weak I∙∙∙O or I∙∙∙Aryl contacts. The different interactions lead to the formation of various assemblies with different dimensions in the solid state. Protonation of the reagents results in formation of entirely different supramolecular structures, which are supported by hydrogen bonding. The structural features of the reagents in the solid state reflects well the behavior in solution, and the I‐C(RF) bond is influenced by coordination of Lewis‐basic solvents to iodine and by hydrogen bonding with protic solvents. These solvent effects are more pronounced in reagents containing the trifluoromethyl fragment than in derivatives with longer RF chains