The reaction of AsCl₃ with H₂L (where L = a rigid dithiolate) results in the self-assembly of As₂L₂Cl₂ supramolecular macrocycles. For ligands 4,4′-bis(mercaptomethyl)biphenyl (H₂1), 4,4′-bis(mercaptomethyl)-trans-stilbene (H₂2), and 1,4-dimethoxy-2,5-bis(mercaptomethyl)benzene (H₂3), the macrocyclic cavities of the resulting assemblies are large enough to host aromatic solvent molecules, as revealed by single crystal X-ray structures of the inclusion complexes. As₂L₂Cl₂macrocycles form in solution as a mixture of diastereomers, but the diastereomers can be selectively crystallized and separated. Crystallization of syn- or anti-As₂3₂Cl₂ can be controlled using host–guest interactions by the prudent choice of crystallization solvents. anti-As₂3₂Cl₂ crystallizes exclusively from chloroform and benzene, while a [(syn-As₂3₂Cl₂)₂·p-xylene] dimer crystallizes from p-xylene and a mixture of [(syn-As₂3₂Cl₂)(anti-As₂3₂Cl₂)·toluene] and [(syn-As₂3₂Cl₂)₂·toluene] dimers crystallize from toluene.