Recent years have seen a vast expansion in the coordination chemistry of p-tert-butylcalix [4]arene (H4TBC [4]), particularly in relation to the synthesis of polynuclear 3d, 4f, and 3d-4f clusters that display a range of fascinating physical properties (e.g. single molecule magnetism and magnetic refrigeration). The calix [4]arene (C [4]) scaffold is an extremely attractive ligand in this regard as it can be synthesised and modified with relative ease, but also because it is predisposed to bind a series of metal ions in the polyphenolic pocket. Furthermore, the conformational properties of C [4]s are well-understood, particularly when the lower-rim comprises only hydroxyl groups, and these molecules can form cone, partial-cone, 1,2alternate and 1,3-alternate conformers. These conformations can also be accessed through the introduction of small substituents at the lower-rim (e.g. OMe), whilst larger groups can be used to lock out a particular conformer as desired. In most cases, this step would preclude the ability to form polynuclear clusters, so it is not of particular relevance to this review and will not be discussed further. The p-tert-butylthia-, sulfonyland sulfinylcalix [4]arene analogues have attracted similar interest in coordination chemistry, building on the fact that their conformations are equally well understood, but also because a common [M4(S -/SO -/SO2 - TBC [4])Cl] n+ (n=2,3) metalloligand results that can be exploited in directed assembly. Notably, this metalloligand has been utilised in the formation of a range of spectacular cage structures that have been exploited in areas such as selective guest / gas uptake and sorption. Some of the larger homologues of H4TBC [4] are highly desirable for exploring polynuclear cluster formation, an example being H9TBC [9] which has been seen to adopt a triple-cone conformation akin to a three leaf clover in the solid state upon complexation to lanthanide ions. This molecule would be very interesting for synthesising highly symmetric polyhedra of 3d / 4f ions but, as is the case for many of the very large homologues, it is (to our knowledge) only accessible in relatively small amounts via laborious synthetic and purification protocols. This therefore hinders the potential utility of the larger HnTBC[n]s in the synthesis of coordination clusters, with the exception of H8TBC [8] which can be isolated on a large scale with ease. Indeed, it has often been found to be an unwanted product in calixarene synthesis. One might intuitively expect H8TBC [8] to behave as two H4TBC [4]s from a coordination chemistry perspective, but the conformations adopted by the octamer upon coordination, coupled with the methylene bridge orientations, preclude such behaviour. To achieve this effect one must tether two H4TBC [4]s through a single methylene bridge from each to afford H8-bis-TBC [4], a ligand that does indeed display augmented coordination chemistry that mimics that of fused C [4]s. It is well known that moving beyond the general C [6] scaffold (i.e. C [7]) leads to a large increase in both flexibility and the associated number of possible conformers in the free calixarene. It therefore follows that, although larger HnTBC[n]s present very exciting opportunities for unearthing new coordination chemistry through favoured coordination modes, there are intrinsic challenges arising from conformational versatility prior to tailoring assembly with such moieties.