Synthesis and crystal structure of the mixed-valence trinuclear cobalt complex {[Co(CN)3(tBuNC)2](μ-CN)[Co(tBuNC)4](μ-CN)[Co(CN)3(tBuNC)2]}

The mixed-valence trinuclear cobalt compound {[Co(CN)3(tBuNC)2](μ-CN)[Co(tBuNC)4](μ-CN)[Co(CN)3(tBuNC)2]} is produced from the reaction of CoCl2 with KCN and tert-butylisocyanide. In the resulting structure two cobalt atoms formally show the oxidation state +III, whereas the central cobalt still exhibits the formal oxidation state +II. All cobalt atoms are octahedrally coordinated by cyanide and isocyanide ligands. The supramolecular structure is determined by C–H⋯O and C–H⋯N hydrogen bonds linking acetone molecules to the trimeric complex as well as connecting the complex units into infinite chains.