Synthesis and crystal structure of anhydrous Na[MnO4]
AbstractThere are numerous reports in the literature about the amount of hydrate water in sodium permanganate, which is said to be between one half and three water molecules per Na[MnO4]. Because no structural descriptions of the hydrate and the anhydrous compound can be found yet, this work reports the synthesis of anhydrous Na[MnO4] via the Muthmann method and its crystal structure. Na[MnO4] crystallizes as dark purple needles in the monoclinic space group P21/n with a = 572.98(5), b = 842.59(7), c = 715.47(6) pm, β = 92.374(3)° and Z = 4. As such and with its isotype to Ag[MnO4], Na[MnO4] completes the series of anhydrous alkali-metal permanganates, comprising Li[MnO4] (orthorhombic, Cmcm, Cr[VO4] type) and the isostructural heavier congeners A[MnO4] (A = K, Rb, Cs; orthorhombic, Pnma, Ba[SO4] type).