On the structure and Mössbauer spectra of ferrous nitroprusside

Monoclinic ferrous nitroprusside trihydrate and its dehydration products have Mössbauer spectra composed of two quadrupole doublets. The quadrupole splitting of the high-spin ferrous cation decreases stepwise as the compound loses water up to the anhydrous state. Cubic ferrous nitroprusside has a complex Mössbauer spectrum with three quadrupole doublets for high-spin ferrous cations, which are determined by the number of water molecules in its environment. The Mössbauer parameters of low-spin ferrous cations in ferrous nitroprusside are practically independent of its hydration degree and crystalline structure.