Anhydrous tin and lead hexacyanoferrates (II)

The crystal structure of Pb 2 Fe(CN) 6 and Sn 2 Fe(CN) 6 has been first determined and refined using the Rietveld method with combined CuKα 1 X-ray and constant-wavelength neutron powder diffraction data in space group P -3 (147, Z =1). The unit cell constants are a =7.1346(1) and 7.1805(1) A, c =5.4531(2) and 5.3639(1) A, respectively. The compounds are layered, groups of three nearest [Fe(CN) 6 ] 4− -complexes are joined to layers by means of Pb or Sn atoms. The same Pb or Sn atoms (c.n.=3+3) joint three nearest complexes from the next layer. The jointing goes through ‘nitrogenlead(tin)nitrogen’ bonds.