Hydrothermal synthesis and structure of a new two-dimensional zincophosphite: Zn₂(HPO₃)₃·H ₂DACH (DACH = 1,2-diaminocyclohexane)

A new open-framework zincophosphite, Zn₂(HPO₃) ₃·H₂DACH 1, was hydrothermally synthesized in the presence of 1,2-diaminocyclohexane (DACH) as structure-directing agent. Its structure was determined by single-crystal X-ray diffraction and further characterized by FTIR, elemental analysis, powder X-ray diffraction and thermogravimetric analysis. Crystal data for 1: M_r = 486.88, monoclinic, space group P2₁/c with a = 10.2287(11), b = 9.7624(11), c = 16.1686(18) Å, β = 92.573(2)°, V = 1612.9(3) ų, Z = 4, D_c = 2.005 g/cm³, F(000) = 984, μ = 3.314 mm^-1 and S = 1.152. The final R = 0.0473 and wR = 0.1121 for 2456 observed reflections with I > 2σ(I). The inorganic layer consisting of four- and eight-membered rings is constructed of alternating ZnO₄ tetrahedra and HPO₃ pseudo pyramids by sharing vertices. The organic template molecules reside in the interlayer region and interact with the inorganic network through H-bonds.