A new tetranuclear defective dicubane azide-bridged cobalt(II) complex

The new tetranuclear cobalt(II) complex with formula [Co4(N3)8(4,5-diazafluoren-9-one)4] (1) is reported. Complex 1 is a cobalt(II) defective dicubane azide-bridged compound showing only azido bridging ligands in the μ1,1– and μ1,1,1– coordination modes. The magnetic properties of 1 are reported. Magnetic susceptibility measurements indicate ferromagnetic coupling. The magnetic data have been fitted to 2 K by considering two different superexchange coupling constants. The out-of-phase signal χM″ displays frequency-dependence below approximately 9 K.

The synthesis of an unprecedented tetranuclear defective dicubane cobalt(II) cage with only azido as bridging ligands is described. In the reported compound the coordination bridging modes of the azido ligand are μ1,1– and μ1,1,1–. As a consequence of the coordination bridging modes the cobalt atoms are ferromagnetically coupled.Figure optionsDownload as PowerPoint slide