The fully deprotonated bisTBC[4] 8-ligands adopt their maximal µ8-bridging mode and thus wrap around the four square faces of the prism, completely encapsulating the [Mn III 4Mn II 2Na6(CO3)2] moiety. The packing found in the extended structure of 2 is markedly different to that outlined above for 1. In this case the clusters are arranged diagonally side on in the ab plane and form a bi-layer type arrangement as shown in Fig. . The TBC [4] sub-units in the bisTBC [4]s shrouding the cluster cores are arranged such that cavities are arranged approximately opposite those of symmetry equivalent assemblies in adjacent bi-layers, behaviour that is also reminiscent of a range of TBC [4] solvates. Inspection of the structure reveals that the closest inter-cluster Mn III •••Mn III distance to be ~13.1 Å, again confirming that this approach of shrouding the clusters with bulky ligands has been successful in isolating cluster cores from one another.