Do CH–Anion and Anion–π Interactions Alter the Mechanism of 2:1 Host–Guest Complexation in Arylethynyl Monourea Anion Receptors?

Selective tuning of arylethynyl urea scaffolds for anionic guests requires an understanding of preferred binding motifs of the host–guest interaction. To investigate the binding preference of receptors without a pre‐organized binding pocket, two electron‐deficient phenylacetylene receptors with a single urea moiety have been prepared and were found to bind halides as 2:1 host–guest complexes that feature key CH–anion or anion–π interactions. These supporting interactions also appear to influence the mechanism of the 2:1 binding event.