Spectroscopic studies of inorganic fluoro-complexes. Part I. The 19F nuclear magnetic resonance and vibrational spectra of hexafluorometallates of Groups IVA and IVB

Abstract

The infrared, Raman, and ¹⁹F n.m.r. spectra of the hexafluoro-anions of the Group IVA and IVB elements have been measured. We conclude that the predominant species present in aqueous solutions of the ammonium salts are the octahedral AF₆ ^2– ions (except where A = Pb, when no definite conclusions could be drawn). In solution, the HfF₇ ^2– ion dissociates into HfF₆ ^2– and F^–. Fluorine exchange is much more rapid when A is Zr, Hf, or Pb than when A is Si, Ge, Sn, or Ti. The tin–fluorine coupling constants in the SnF₆ ^2– ion are appreciably solvent-dependent.