Octa- and hexametallic iron(iii)-potassium phosphonate cagesCCDC reference numbers 824892 (1a·2MeOH), 824893 (1b·MeOH) and 824891 (2·2MeOH). For crystallographic data in CIF or other electronic format see DOI: 10.1039/c1dt10855g

Two new iron( iii )-potassium phosphonate cage complexes with {K 2 Fe 6 } and {K 2 Fe 4 } cores are reported. Magnetic studies reveal antiferromagnetic interactions between the Fe( iii ) centres occur in these cages. Use of acetylacetonate as a ligand to block coordination sites of Fe( iii ) centres leads to two new polymetallic iron phosphonate cages.