Examination of the extended structure found in 1 reveals similar packing behaviour to that observed for [Cu9] analogues. As in those examples, the overall triangular shape of 1 drives packing of symmetry equivalents to form layers in the ab plane (Fig. ) in which TBC [4] cavities are arranged opposite regions in clusters that are reminiscent of TBC [4] itself. Although it is impossible for such species to form bi-layers that are preferred by solvates of TBC [4], these assemblies do display bi-layer type behaviour within layers. Inspection of the extended structure reveals the closest inter-cluster Mn III •••Mn III distance to be ~15.75 Å, and between layers this is shorter at ~12.71 Å. In both cases these are well-isolated by the TBC [4] ligands and packing of the assemblies. . The crystals were found to be in a triclinic cell and structure solution was carried out in the space group P-1 with the ASU comprising half of the formula. The metallic skeleton describes a [Mn III 4Mn II 2Na6] tetracapped square prism with the Mn II /Na ions sitting on the vertices of the square prism and the Mn III ions capping the square faces. Disordered [CO3] 2-ions occupy the inside of the cage, positioned to bridge between four vertex metal ions (Na1-3, Mn3) and two capping metal ions (Mn1*, Mn2). The four face-capping Mn III ions are housed in the polyphenolic pockets of the two fully deprotonated bis-calixarene ligands whose O-atoms further bridge to the Mn II /Na I ions in the square prism.