Revisiting Sodium Hexafluoroiridates: Perspective Precursors for Electronic, Quantum, and Related Materials.

The following salts have been synthesized and structurally characterized: Na2[IrF6]·2H2O (C2/m, a = 6.6327(4), b = 10.0740(6), c = 5.9283(5) Å, β = 122.3880(10)°) and Na3[IrF6]·2H2O (R-3, a = 7.5963(3), b = 7.5963(3), c = 9.8056(4) Å) (for the first time) by single-crystal X-ray diffraction; the unit cell parameters of a tetragonal phase (P4 2/mnm, a = 5.005(2), c = 10.074(4) Å) of the stable α-Na2[IrF6] were determined for the first time; and the unit cell parameters of β-Na2[IrF6] (P321, a = 9.332(4), c = 5.136(2) Å) and Na3[IrF6] (P21/n, a = 5.567(4), b = 5.778(4), c = 8.017(2) Å, β = 90.41(2)°) were determined using powder X-ray diffraction (PXRD). The data of the thermal stability was obtained by differential thermal analysis (DTA) for all substances. The presence of Na3[IrF6]·H2O monohydrate is predicted. H2[IrF6] was prepared in a solution and was demonstrated to behave as a strong dibasic acid.