Organic molecular tessellations and intertwined double helices assembled by halogen bonding

Abstract

Isomeric 2,5- and 2,6-bis(iodoethynyl)pyrazine have been employed to assemble single-component polygonal molecular tessellations and intertwined double helices via intermolecular ethynyl C—I⋯N halogen bonding. X-ray crystallography elucidated the 3D supramolecular architectures of five ditopic heteroaromatic polymorphs obtainable via crystallization in various organic solvents.