Un nouveau diarséniate Cs₃Fe₂(AsO₄)₃ à environnement exclusivement pentagonal du fer

The crystal structure of the new iron(III) arsenate, viz. tricaesium diiron(III) tris(arsenate), Cs₃Fe₂(AsO₄)₃, is built up from corner-sharing AsO₄ tetrahedra and FeO₅ trigonal bipyramids forming a three-dimensional open framework, which contains two channels running along the c axis where the Cs⁺ cations are located. This compound is a rare example of an oxide possessing Fe exclusively in trigonal-bipyramidal coordination.

Sel mixte de lithium et de sodium eicosahydrate, Na_5.22Li_0.78[V₁₀O₂₈]·20H₂O

The structure of the title compound, sodium lithium decavanadate eicosahydrate, Na_5.22Li_0.78[V₁₀O₂₈]·20H₂O, is characterised by [V₁₀O₂₈]^6- polyanions which are linked by hydrogen bonds and Na⁺ ions. The centrosymmetric [V₁₀O₂₈]^6- polyanion consists of ten distorted VO₆ edge-sharing octahedra.