Tetraalkylphosphonium polyoxometalates: Electroactive, "task- specific" ionic liquids

The pairing of selected polyoxometalate (POM) anions with appropriate tetraalkylphosphonium cations, which display an original family of ionic liquids, is discussed. The ionic liquids exhibit both an ability to solvate a remarkable variety of organic and inorganic materials and negligible vapor pressures, making the liquid solids potential green reaction media. The POM, a family of metal-oxygen cluster anions, offer the basis for unique TSIL as they are inherently functional and require no derivatization. POMs are virtually unmatched in terms of their compositional and structural diversity, suggesting that a wide range of ILs could become accessible upon their pairing with an appropriate cation. Differential scanning calorimetry(DSC) and TGA were also employed to characterize the phosphonium-Lindqvist IL, the desirable properties of which include satisfactory thermal stability and a wide liquid range.