Conceptually similar to HBs, electrostatic interactions arising from the donation of electron density into electropositive regions, labelled σ-holes, on halogen and chalcogen atoms have been termed halogen bonds (XBs) and chalcogen bonds (ChBs), respectively (Fig. ). Whilst less well studied than their HB congeners, XBs and ChBs have been investigated as alternatives non-covalent interactions in supramolecular chemistry, including for self-assembled architectures.