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 [enH2]0.5Zn[(L)(H2O)]·H2O (1) and [enH2]0.5Zn5[(HL)(L)3(H2O)2]·3H2O (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)2NH3]2+ cations.