Synthesis, spectroscopic and structural characterisation of periodate complexes of iron(III)

Abstract

The reaction of Fe(NO₃)₃·9H₂O with NalO₄ in aqueous acid solution gave brown [Fe₄I₃O₂₄H₁₅] and subsequent reaction with concentrated alkalis formed M_n[Fe₄l₃O₂₄H_15–n](M = Li, Na, K, Rb or Cs). The crystal structure of K₆Na₂[Fe₄l₃O₂₄H₇]·14H₂O has been determined and shown to contain an Anderson-type anion composed of seven edge-linked octahedra. In the crystal studied a central FeO₆ group is surrounded by six disordered FeO₆ and IO₆ groups. All the prepared salts have been shown to contain a similar anion based upon spectroscopic data, iron and iodine K-edge extended X-ray absorption fine structure data, and the ⁵⁷Fe Mössbauer spectra.