Polyiron(lll) Oxyhydroxide Clusters: The Role of Iron(lll) Hydrolysis and Mineralization in Nature

The compounds which form in aqueous solutions containing iron(III) and chelating ligands are considered and the control of iron(III) hydrolysis as a synthetic strategy for the preparation of iron(III) species of different nuclearities is explained. The relevance of such complexes to naturally occurring iron species is discussed. Hydroxide, oxide. carboxylate and alkoxide bridged iron(III) aggregates are compared to iron(III) clusters in Nature with particular attention paid to the way in which their formation can aid in understanding the biomineralization of iron. The structures of trapped mineralized iron(HI) oxyhydroxide clusters are proposed as good models for the iron storage protein ferritin, which itself is best regarded as a cluster species. Synthetic strategies for producing dusters of different shapes and sizes are suggested.