The direct synthesis and characterization of alkali metal hexafluorochromates (iii), M^I₃CrF₆

The reduction of an aqueous solution of CrO3 with hydrazine hydrate in the presence of an excess of equimolar amounts of MI OH and 40% HF yields green, crystalline alkali hexafluorochromates(III), MI3CrF6 (MI= NH4, Na, K or Rb), in very high yield. The lithium analogue has been prepared by using Li2CO3 instead of lithium hydroxide. The compounds have been characterized by elemental analyses, room temperature magnetic moments, infrared spectra and molar conductivity. Time dependent molar conductivity studies of (NH4)3CrF6 and K3CrF6 suggest that the compounds do not undergo decomposition in water at ambient temperatures