The crystal structure of Tutton's salt type K2[Co(H2O)6](SO4)2. A combined X-ray and neutron study

Abstract

Abstract The crystal structure of dipotassium hexaaquacobalt(II) sulfate, K2[Co(H2O)6](SO4)2, has been determined at room temperature by single crystal X-ray diffraction. The deep purple crystals grown from aqueous solution are monoclinic, space group P21/a, with unit cell dimensions a = 9.057(1) Å, b = 12.211(2) Å, c = 6.155(1) Å, β = 104.82(1)°, Z = 2, D c = 2.207 Mg/m3. The hydrogen atom positions were obtained from a Rietveld refinement on neutron powder data measured on a deuterated sample. Fixing these positions in the X-ray structure refinement on 1162 unique reflections (I > 2σ) resulted in R(F) = 0.0188, wR(F 2) = 0.0504, GOF = 1.14. All structural details compare well with corresponding results reported for other members of the Tutton's salts series.