Single crystal X-ray studies of (6)·(tetrahydrofuran)₂ and (6)·(benzene)_1.5 reveal the presence of two distinct types of dimeric edge–edge C–HN packing motifs. All of the racemic dibromides 2–4 and 6 form clathrate compounds where their opposite enantiomers are joined edge–edge by means of C–HN dimers. Hence this interaction is robust and of considerable value in crystal engineering. Modification of the benchmark centrosymmetric aryl–HN dimer can result, however, in more complex modifications which better suit a given host–guest combination. Therefore a range of different C–HN dimers is observed, with the new motif present in (6)·(benzene)_1.5 completing a sub-set of these variants. This structural adaptability increases the likelihood of inclusion because competition between many weak intermolecular contacts is a central part of the host design philosophy.