Four polymetallic iron complexes have been synthesised by a high-temperature route. Two complexes have a [Fe6O2(OH)(2)](12+) core, one containing benzoate ligands and the other pivalates. The other two have a [Fe11O6(OH)(6)](15+) core, with benzoate or t-butylacetate bridging ligands, respectively. These complexes have been characterised by X-ray crystallography, elemental analysis and magnetochemistry. All four complexes consist of Fe-III ions, and anti-ferromagnetic exchange between the metal centres lead to low spin ground states. (C) 2004 Elsevier Ltd. All rights reserved.