The coordination chemistry of p-tert-butylcalix[4]arene with paramagnetic transition and lanthanide metal ions: an Edinburgh Perspective

The calix[4]arene scaffold is an extremely versatile supramolecular platform that has found widespread use across many research areas due to its synthetic versatility, controllable conformation, and the presence of cavities or clefts for tailorable guest binding. The tetraphenolic lower-rim of p-tert-butylcalix[4]arene in the cone conformation is ideal for binding a variety of paramagnetic transition and lanthanide metals, and in this Perspective we review our endeavours in using such complexes as metalloligands in the synthesis of polymetallic clusters that have fascinating structural and magnetic properties. By varying reactants, stoichiometries and reaction or crystallisation conditions it is possible to access an incredible range of clusters, all of which show consistent trends in coordination preferences and assembly behaviours. p-tert-Butylcalix[4]arene has already given so much, yet it is likely that this remarkable parent calixarene will continue to surprise chemists and deliver even more in terms of novelty and function.