ChemInform Abstract: Preparation and Crystal Structures of Hg3(NbF5)2SO4 (I), Hg3(TaF5)2SO4 (II), and Hg4(Ta2F11)2 (III).

Abstract (I) and the isostructural (II) are obtained as minor products during the reactions of Hg with SO 2 solutions of Hg(MF 6 ) 2 (M: Nb, Ta) (20 °C, 2 months, yields not given).