Fig. 4. ESI-MS spectra of the solution containing the isolated tetrahedron Tet-1 (a). The aforementioned solution upon the addition of (b) Bu₄NBr, (c) Bu₄NI and (d) Bu₄NDSA, showing the formation of interlocked structures with a 7Br^– ⊂ Zn₈L₈ core, 7I^– ⊂ Zn₈L₈ core and host–guest DSA ⊂ Tet-1 species, respectively.