Under suitable conditions, HB capsules have been shown to be capable of encapsulating a variety of guest species, both neutral and charged, and to exhibit guest selectivity. 148 Such host-guest chemistry has been exploited for applications in catalysis, 161 molecular separations, 162 and stabilisation of reactive species. 163 Fig. Halogen-and chalcogen-bond interactions, including with halonium ions, can be used to assemble both homo-and heteromeric capsules. R groups omitted from SCXRD structures for clarity.