Study by X-ray crystallography and Mössbauer spectroscopy of the hexacyanoferrate(III) compounds Cs2M[Fe(CN)6](M = Li, Na, or K)

Abstract

The crystal structures of Cs₂Na[Fe(CN)₆](I) and Cs₂K[Fe(CN)₆](II) have been elucidated by single-crystal X-ray analysis and compared with that of Cs₂Li[Fe(CN)₆]. Crystals of both are monoclinic, space group P2₁/n, with Z= 2 in unit cells of dimensions: (I), a= 10.870(1), b= 7.709(1), c= 7.573(1)Å, β= 89.994(6)°: (II), a= 11.140(1), b= 8.131(1), c= 7.660(1)Å, β= 90.165(7)°. The Mössbauer spectra of the series are discussed with particular reference to lattice dynamics, and to electronic spin-relaxation of the t_2g⁵ S =½ configuration.