Mutual stabilisation between MII4L6 tetrahedra and MIIX42− metallate guests
A complex host–guest equilibrium employing metal ions incorporated into both the host and guest is discussed. MIIX42− metallate guests are shown to provide a good size and shape match for encapsulation within the M4L6 tetrahedral capsules, facilitating the generation of previously unreported Zn4L6 complexes. Displacement of the initial, primary template anion (ZnBr42−) by a secondary template anion (ClO4−) is shown to result in the formation of a pentagonal-prismatic Zn10L15 structure that incorporates both Br− and ClO4−. Furthermore, the formation of heterometallic complexes provides direct evidence for metal exchange between the guest and host complex.