Hydrothermal synthesis and characterization of a novel crystal containing [Co4O4]4+ cubane core: [Co4O4(dpaH)4(CH3COO)2]2V4O12 · 5H2O

The hydrothermal reaction of Co(CH3COO)2 · 4H2O, NaVO3, 2,2′-dipyridylamine (dpaH) and H2O yielded a novel crystal [Co4O4(dpaH)4(CH3COO)2]2V4O12 · 5H2O, which was characterized by X-ray structure analysis. The crystal structure is composed of an isolated molecular unit [V4O12]4− and two [Co4O4(dpaH)4(CH3COO)2]2+ moieties. The cobalt atoms and the bridging-oxygen atoms are introduced as structure-directing components and form the [Co4O4] cubane core. As the Nsingle bondCosingle bondN bond angles increase, the Osingle bondCosingle bondO bond angles of the acetate-bridged top and bottom faces decrease and the four-membered cobalt–oxygen rings are more distorted.