Halogen‐Bond‐Mediated Assembly of a Single‐Component Supramolecular Triangle and an Enantiomeric Pair of Double Helices from 2‐(Iodoethynyl)pyridine Derivatives

Construction of single‐component supramolecular triangle and unprecedented spontaneous resolution of pairs of intertwined supramolecular 31‐ and 32‐double helices by the self‐assembly of achiral 2‐(iodoethynyl)pyridine and its derivatives have been achieved through intermolecular ethynyl C−I⋅⋅⋅⋅N halogen bonds in the crystalline state. Fine‐tuning of the molecular structure of the achiral monomer and choice of solvents for crystallization have a dominant effect on the resultant supramolecular architectures. The shape of things to come: Crystallization of 2‐(iodoethynyl)pyridine in acetonitrile led to the supramolecular assembly of a single‐component halogen‐bonded triangle. Spontaneous resolution of a pair of double helices of opposite helicities was observed for 2‐(iodoethynyl)quinoline.