Mikhail Sofin, Hans-Ulrich Güdel, Roland Bircher, Eva-Maria Peters and Martin Jansen
Na₁₀Co₄O₁₀, an Oligooxocobaltate(II, III) with Unusual Magnetic Properties
Angew. Chem. 115, 3651-3653 (2003)                 
Angew. Chem. Int. Ed. 42, 3527-2529 (2003)                 

Abstract: (Article without Abstract)
Graphical Abstract: The novel mixed-valent oligooxocobaltate can be synthesized through a direct reaction by the azide/nitrate route. The magnetic properties of the compound are characterized by the strongly distinct hierarchy in the magnetic exchange interactions within the complex anion (see picture).