The “Nitrogen Effect”: Complexation with Macrocycles Potentiates Fused Heterocycles to Form Halogen Bonds in Competitive Solvents

Weak intermolecular forces are typically very difficult to observe in highly competitive polar protic solvents as they are overwhelmed by the quantity of competing solvent. This is even more challenging for three‐component ternary assemblies of pure organic compounds. In this work, we overcome these complications by leveraging the binding of fused aromatic N‐heterocycles in an open resorcinarene cavity to template the formation of a three‐component halogen‐bonded ternary assembly in a protic polar solvent system. Fused aromatic N‐heterocycle quinoline templates a halogen‐bonded ternary assembly with resorcinarene and 1‐iodonoonafluorobutane in a highly competitive solvent environment, while phenanthroline templates a dimeric capsule in pure methanol.