Crystallisation of the tetrahaloaryl host 2,4,10,12-tetrabromo-6,7,14,15-tetrahydro-6,14-thiacycloocta[1,2-b:5,6-b′]diquinoline 7 from benzene, chloroform, 3-methylpyridine, 4-methylpyridine, 2-methylpyridine, or tert-butylcyclohexane, yields a series of closely related inclusion compounds (7)₂·(guest) in space group P. Two host molecules surround a single guest to form a penannular repeat unit in each of these crystal structures. Structural variation arises from the differing guest sizes, shapes and interactions. The corners of four molecular pens are linked by utilising novel S/Br clusters as supramolecular synthons: S₂Br₄ for the first four compounds, and S₂Br₆ for the latter two cases. The aromatic faces of the repeat units associate through offset π⋯π interactions. Aromatic edge–edge linkage occurs in the former group of compounds by means of N₂Br₂ and N₂Br₄ clusters, but these are absent in the final two structures. Mesitylene (1,3,5-trimethylbenzene) is too wide for penannular inclusion. It yields an alternative layer structure, (7)·(mesitylene), also in P. This compound is stabilised by means of host–guest C–H⋯π associations, plus host–host aromatic and S⋯Br⋯Br⋯N interactions.