Hydrothermal synthesis and structural characterization of an organically-templated zincophosphite: [C4N2H12]0.5·[Zn3(HPO3)4]·H3O

A new three-dimensional organically templated [C4N2H12]0.5·[Zn3(HPO3)4]·H3O was hydrothermally synthesized and characterized by single crystal X-ray diffraction. The three-dimensional framework is built up from two-dimensional layers with 4.8-membered rings and one-dimensional chains of 4-membered rings. The structure has strictly alternating ZnO4 tetrahedra and HPO3 pseudo pyramids which are linked through their vertices giving rise to the three-dimensional architecture with 8,12-membered ring channels. The protonated water molecules and diprotonated piperazine are located in the 8-membered and 12-membered channels, respectively. The compound crystallizes in monoclinic system, space group P21/n with cell parameters, a=9.6739(16) Å, b=8.4528(13) Å, c=20.257(4) Å, β=97.966(5)°, Z=4, R=0.023, and Rw=0.060. It was characterized by the powder X-ray diffraction, differential thermal-thermogravimetric analyses, IR spectroscopy and proton-decoupled 31P MAS NMR solid-state spectroscopy.