Engineering Supramolecular Systems with a Bis(pyridyl)azine Derivative and Different Hydrogen and Halogen Donors.

Cocrystal engineering has become an essential strategy in materials science, enabling the design of new solid-state systems through the rational combination of organic components guided by noncovalent interactions. In this study, the cocrystallization of a bis-pyridyl-azine substrate with three different coformers, namely, 1,3,5-triiodo-2,4,6-trifluorobenzene, 1,2-diiodotetrafluorobenzene, and 4,4'-biphenol, led to the formation of five new cocrystal systems. The supramolecular architectures of these materials were investigated with a focus on the role of halogen bonding and hydrogen bonding in crystal packing. All observed noncovalent interactions were investigated using density functional theory (DFT) calculations carried out with the ωB97XD functional and the def2-TZVPP. The results emphasize the influence of molecular recognition in the self-assembly process and reveal how halogen and hydrogen bonds act as key driving forces in the formation and stabilization of these cocrystals.