Synthesis and characterization of [PW11O39Ir(H2O)]4−: successful incorporation of Ir into polyoxometalate framework and study of the substitutional lability at the Ir(iii) site

The first Keggin-type heteropolyanion, [PW11O39Ir(H2O)]4− (1), was synthesized by hydrothermal reaction from two different polytungstate precursors and [IrF6]2−. It was isolated as (Bu4N)4[PW11O39Ir(H2O)] (1a), which was completely characterized by multinuclear 31P and 183W NMR, ESI-mass spectrometry and cyclic voltammetry. A rapid screening methodology to ascertain the intrinsic substitutional lability at the Ir site is also presented, based on ESI-MS.