Syntheses and crystal structures of two uranyl peroxide nanoclusters with a diphosphonate linker ligand

Abstract Two uranyl peroxide nanoclusters with etidronate ligand [L = (PO3)2C(OH)CH3]4-] have been prepared via self-assembly in aqueous solutions and structurally characterized. K40[(UO2)20(O2)20L10]·nH2O (1) has a barrel-shaped structure constructed by linking two pentagonal and one decagonal uranyl peroxide rings with ten etidronate ligands. K38[(UO2)26(O2)33L6]·nH2O (2) has a round top and flat bottom structure constructed by linking a double connected pentagonal uranyl peroxide unit (U8) and a dome-shaped uranyl peroxide unit (U18) with six etidronate ligands. The presence of uranyl ion, peroxide and etidronate ligands has been confirmed by Raman spectroscopy and the role of K+ counter ions on the formation of such clusters has been examined.