The stereochemistry of hexachloroantimony(III) compounds

Abstract

The hexachloroantimony(III) anion, SbCl₆^3– is shown to be octahedral in aqueous solution, but distorted in the solid compounds M₃SbCl₆(M = NH₄, K, Rb, or Cs) which have been prepared in liquid sulphur dioxide. The anion is also distorted in the compound [Co(NH₃)₆]SbCl₆ where it was previously thought to be octahedral. Comparison of the Sb–Cl stretching force constant in SbCl₆^3– and SbCl₆^– indicates that the Sb–Cl bond is of very similar strength in both complex anions.