By using environmentally friendly K3[Co(CN)6] as a cyanide source, the solvothermal reaction of CuCl2 and tetrazole (Htta) led to a novel tetrazolate- and cyanide-bridged three-dimensional heterometallic CuII-CoIII complex, namely poly[[hexa-μ2-cyanido-κ12C:N-pentakis(μ3-tetrazolato-κ3N1:N2:N4)cobalt(III)tetracopper(II)] monohydrate], {[CoIIICuII4(CHN4)5(CN)6]·H2O}n, (I). The crystal structure analysis reveals that it is the first example of a (6,8,8)-connected three-dimensional framework with a unique topology, constructed from anionic [Co(CN)6]3- and cationic [(Cu1)2(tta)2]2+ and [(Cu2Cu3)(tta)3]+ units through μ2-cyanide and μ3-tetrazolate linkers. The compound was further characterized by thermal analysis, vibrational spectroscopy (FT-IR), scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM-EDS) and magnetic measurements. The magnetic investigation indicates that the complex exhibits antiferromagnetic coupling between adjacent CuII cations.
Keywords: antiferromagnetic coupling; crystal structure; heterometallic; hexacyanidocobaltate; tetrazolate ligand; three-dimensional coordination polymer.