Coordination compounds of Mn maintain long standing interest across a breadth of topics from bioinorganic chemistry 1 to molecular magnetism. Key to manipulating and enhancing physicochemical behaviour for any application is structural control, and for polymetallic compounds the self-assembly process and identity of the final product is largely dominated by choice of bridging ligand. We, and others, have employed p-t Bu-calix [4]arene (H4TBC [4], Fig. ) for the synthesis of a range of transition metal (TM) and lanthanide metal (LnM) species in which the TM/LnM-TBC [4] moiety acts as a metalloligand that encapsulates an oxo/hydroxo-bridged polymetallic core. Structurally, this means it acts as a capping vertex in the resulting metallic skeleton. The calix [4]arene tetraphenolic pocket is particularly well suited to bonding Jahn-Teller (JT) distorted ions such as Cu and Mn III because it will preferentially coordinate metals possessing four short equatorial and two long axial bonds. Illustrative examples include the complexes [Cu II 9(OH)3(TBC [4])3Cl2(DMSO)5.5(EtOH)0.5][Cu I Cl2] (1, Fig. ) and [Mn III 2Mn II 2(OH)2(TBC [4])2(dmf)6] (2, Fig. ). In the former the TM-TBC [4] metalloligand encapsulates a [Cu II 6(OH)3] trigonal prism, and in the latter a [Mn II 2(OH)2] dimer. This general bonding motif has been observed in the vast majority of TM/LnM complexes we have isolated under ambient conditions and this has allowed us to develop a specific set of empirical metal ion binding rules for TBC [4]. (A) TBC [4] preferentially binds TM III ions;