Self-assembly of water cluster in iron(III) oxalate-bridged complexes

The synthesis and crystal structural characterization of the compound of formula {[FeII(phen)3]2[Fe2IIIox5]}·11H2O (1) has been reported. The most interesting feature of the solid state structure of 1 is the formation of decanuclear water clusters self-assembled by means of hydrogen bonding interactions between water molecules. The (H2O)10 clusters display extensive multiple interactions with the dimeric units, leading to the formation of an extended 3D supramolecular assembly, wherein hexameric water clusters interconnected with dodecameric hybrid water-Ooxalate clusters can be recognized. The comparison of this supramolecular architecture with that found in the already known compound of formula [Fe(bpm)3]2[Fe2(ox)5]·8H2O (2) allows some preliminary observations on the design and control of hydrate formation depending on the size and shape of templating cations.