Hydrothermal synthesis and structures of materials of the M(II)/tetrazole/sulfate family (M(II) = Co, Ni; tetrazole = 3- and 4-pyridyltetrazole and pyrazinetetrazole)

Hydrothermal reactions of cobalt or nickel sulfate with the appropriate substituted tetrazole yielded a series of compounds of the M(II)/tetrazolate/sulfate family. While the parent compound [Co(prztet)2(H2O)2]·0.5H2O (1·0.5H2O; prztet = pyrazinetetrazolate) is molecular, the remaining materials exhibit extended structures. Thus, [Co2(4-pyrtet)(SO4)(OH)(H2O)]·1.5H2O (2·1.5H2O), [Co3F2(SO4)(3-pyrtet)2(H2O)4] (4) and [Ni3F2(SO4)(3-pyrtet)2(H2O)4] (5) are two-dimensional, in contrast to [Co4(prztet)6(SO4)(H2O)2] (3) and [Ni5(3-pyrtet)4(SO4)2(OH)2(H2O)2]·0.5H2O (6·0.5H2O) which are three-dimensional (3-pyrtet = 3-pyridinetetrazolate; 4-pyrtet = 4-pyridinetetrazolate). The sulfate-containing phases exhibit a variety of cluster-based secondary building units: variants of the common trinuclear motifs in 2, 4 and 5, a tetranuclear cluster core in 3, and a pentanuclear building block in 6. The sulfate ligands adopt monodentate and μ2-, μ3- and μ4-bridging modes in the structures.

Graphical abstractHydrothermal reactions of cobalt or nickel sulfate with the appropriate substituted tetrazole yielded a series of compounds of the M(II)/tetrazolate/sulfate family. The two-dimensional structure of [Co2(4-pyrtet)(SO4)(OH)(H2O)] is illustrated.Figure optionsDownload full-size imageDownload as PowerPoint slide