(B) TBC [4] will bind TM II ions in the absence of TM III ions; (C) TBC [4] will bind LnM III ions in the absence of TM II or TM III ions. As an extension to this science we have recently begun investigating the coordination chemistry of 2,2'-bis-p-t Bu-calix [4]arene (H8L), which contains two TBC [4] units linked at the methylene bridge (Fig. ). The conformational flexibility (ring inversion) of TBC [4] in solution is well understood and when applied to H8L upon coordination-driven self-assembly it proffers a ligand with eight phenolic O-atoms in close proximity and oriented in the same direction. Initial studies have shown that H8L displays a systematic extension of the empirical metal ion binding rules established for TBC [4], rather than, for example, mimicking the behaviour of p-t Bu-calix [8]arene.