Elucidating the Binding Mode of Sulfur‐ and Selenium‐Based Cationic Chalcogen‐Bond Donors

Abstract

AbstractFor a comparison of the interaction modes of various chalcogen‐bond donors, 2‐chalcogeno‐imidazolium salts have been designed, synthesized, and studied by single crystal X‐ray diffraction, solution NMR and DFT as well as for their ability to act as activators in an SN1‐type substitution reaction. Their interaction modes in solution were elucidated based on NMR diffusion and chemical shift perturbation experiments, which were supported by DFT‐calculations. Our finding is that going from lighter to the heavier chalcogens, hydrogen bonding plays a less, while chalcogen bonding an increasingly important role for the coordination of anions. Anion‐π interactions also show importance, especially for the sulfur and selenium derivatives.