Hydrothermal Synthesis, Crystal Structures, and Thermal Stabilities of Two New Zinc Phosphonates with a Layered and a 3D Framework Structures

By using ethylenediamine as a structure-directing agent, two new zinc phosphonates [enH(2)](0.5)Zn[(L)(H2O)]center dot H2O (1) and [enH(2)](0.5)-Zn-5[(HL)(L)(3)(H2O)(2)]center dot 3H(2)O (2) (H3L = H2O3PCH(OH)CO2H, en = ethylenediamine), have been synthesised by hydrothermal reaction and structurally characterised by single crystal X-ray diffraction as well as with infrared spectroscopy, elemental analysis and thermogravimetric analysis. The structure of compound 1 comprises ZnO6 octahedra and CPO3 tetrahedra connected by [O3PCH(OH)CO2](3-) to form a 2D layered structure with one-dimensional channel system along the a axis, and the protonated ethylenediamine cations are being located between two adjacent layers. In compound 2, the connections of alternately arranged ZnO6, ZnO5 polyhedra, and CPO3 tetrahedra result in a 3D framework structure with channels containing the [NH3(CH2)(2)NH3](2+) cations.