Hexafluoro antimonates(V) of divalent metals, synthesis and properties

Abstract

Solvolysis of metal(II) fluorosulfates in liquid antimony(V) fluoride according to:[Formula: see text]with M = Sn, Ni, Pd, Cu, or Ag, is found to be a clean, efficient route to the hexafluoro antimonates of the corresponding metals. Two of the compounds reported here display unusual features: Pd(SbF6)2 is, like its fluorosulfate precursor, paramagnetic with the Pd2+ ion in a 3A2g ground state, and an analysis of the ligand field spectrum is presented; Ag(SbF6)2 is, unlike a recently reported paramagnetic, blue, valence isomer, diamagnetic and nearly white in color. Formulation as a mixed valency compound Ag(I)Ag(III)(SbF6)4 is suggested. Low temperature magnetic susceptibility measurements (where appropriate), Raman, and IR data are reported. The hexafluoro antimonates of Ni, Pd, and Cu show antiferromagnetic exchange at very low temperatures. Pd(SbF6)2 shows very weak ferromagnetism below 10 K. Keywords: fluoroantimonates of divalent metals, synthesis and solvolysis in SbF5, vibrational spectra, magnetic susceptibility measurements.