Here it is very clear that the coordination chemistry of H8TBC [8] with Fe is almost completely unknown, with only three heterometallic complexes published, two rooted in Fe carbonyl chemistry, with the other being an Fe-s block complex. There are zero examples of homometallic Fe clusters in any oxidation state and no clusters containing more than four Fe centres. The calix [8]arene ligands are present in either their fully deprotonated, TBC [8]/C [8], or doubly protonated, H2TBC [8], forms in distorted saddle and double-cone conformations, respectively. The O(Ph) atoms of the ligands adopt two bonding motifs -terminal, with neighbouring atoms chelating the same metal centre, and µ-bridging. In each case the latter directs the formation of {Fe2} dimers.