Halogen bonding is a class of directional noncovalent interactions formed between the σ-hole of a halogen atom and a nucleophile. Classical halogen bonding originates from the σ-hole generated along the bond axis of an electroneutral halogen atom (I, Br or Cl) covalently linked to an electron-withdrawing substituent, and is characterized by high directionality and tunable bond energies, making it suitable for the construction of open and expandable supramolecular networks. Cationic halogen bonding, in contrast, involves a halonium ion (X^＋) coordinating simultaneously with two Lewis bases through its p-orbital vacancy, giving rise to the characteristic three-center four-electron [D…X…D]^＋ motif, with bond energies reaching up to 180 kJ•mol^－1. This interaction exhibits both covalent and electrostatic character, endowing it with exceptional thermodynamic stability and bidentate bridging capability. On the basis of these distinctions, the structural construction logic and dimensionality control strategies of both types of halogen-bonded systems in supramolecular self-assembly are systema- tically reviewed, covering zero-dimensional to three-dimensional architectures including dimers, capsules, helical polymers, two-dimensional halogen-bonded organic frameworks (XOFs), and three-dimensional crystalline frameworks, with emphasis on the distinct contributions of the “monodentate linear connectivity” of classical halogen bonds and the “bidentate bridging nodes” of cationic halogen bonds to assembly topology and stability. Furthermore, the functional applications of these halogen-bonded assemblies in photocatalysis, gas separation, and biomedicine are summarized. The complementary features of classical and cationic halogen bonds in terms of directionality, bond strength, and assembly behavior provide a rich design space for crystal engineering and functional materials.

Key words: halogen bond, supramolecular self-assembly, noncovalent interaction, crystal engineering, halogen-bonded organic framework