Intercalated brucite-type layered cobalt(II) hydroxysulfate

Abstract

In an attempt to synthesize new cobalt(II) sulfate framework structures using 1,4-diazabicyclo[2.2.2]octane as a template, crystals of poly[0.35-[hexaaquacobalt(II)] [tri-μ-hydroxido-μ-sulfato-dicobalt(II)]], {[Co(H2O)6]0.35[Co2(OH) 3(SO4)]}n, were obtained as a mixture with [Co(H2O)6]SO4 crystals. The crystal structure can be described as being constructed from discrete brucite-type [Co 4(OH)6(SO4)2] layers, each of which is built up from edge-shared [Co(OH)6] and [Co(OH) 4-(OSO3)2] octahedra, with partial intercalation by [Co(H2O)6]2+ ions. The absence of ca 30% of the [Co(H2O)6]2+ cations indicates partial oxidation of cobalt(II) to cobalt(III) within the layer.