The hypothetically reversible [Cu(I)(diallylsulfoxide)] ↔O2 [Cu(II)(diallylsulfide)] system was examined by FTIR spectroscopy and X-ray diffraction. It is stated that the Cu4OCl6 body centered adamantanoid cages, appearing at both the substrate and product sites, act as a template to promote the oxidation of diallylsulfide to diallylsulfoxide or Cu(I) to Cu(II), thus making the reaction irreversible. Each of these two adamantanoid cores possesses a different point symmetry as well as self assembly mode to form two polymorphs of the [Cu4OCl6(diallylsulfoxide)4] complex. Their polymorphic relationships based on the symmetry homology S4 ← Td → C3, as well as the distortion in the Cu(II) coordination geometry, are discussed.