Some consequences of the lone pair in hexafluorostannates (II) hexahydrates studied by 119Sn and 57Fe Mössbauer spectroscopy

119 Sn Mossbauer-effect measurements have been performed on the metal(II) hexafluorostannates(II) hexahydrates with M=Fe, Zn and Ni in the temperature range 4.2-300 K. The lattice parameters calculated from the hyperfine Mossbauer data are correlated to the structure and the existence of a lone pair at the tin atom with a large p-character. The stereochemical activity of this electronic pair is illustrated by a particulary large Goldanskii-Karyagin effect, due to the electrostatic repulsion between the lone pairs