Hydrothermal Synthesis,Crystal Structure,and Characterization of Two New Metal Diphosphonates with a 3D Pillared Layered Structure

Two new metal diphosphonates with a 3D pillared layered framework, Zn₂L] · 2H₂O ( 1 ) and Sb(HL)(H₂O)] · H₂O ( 2 ) (H₄L = H₂O₃PCH₂NC₄H₈NCH₂PO₃H₂), were synthesized under hydrothermal conditions and structurally characterized by single‐crystal X‐ray diffraction as well as IR spectroscopy, elemental analyses, and thermogravimetric analyses. For compound 1 , each ZnO₃N tetrahedron is in turn corner‐sharing through three CPO₃ tetrahedra from three different phosphonate ligands to form two‐dimensional inorganic layers in the ab plane. In compound 2 , the inorganic puckered layers are composed of pseudo‐octahedral bipyramidal SbO₅ and CPO₃ tetrahedra in the bc plane. The overall structure of both compounds may be described in terms of alternating inorganic infinite layers and organic pillars{–CH₂N(C₂H₄)₂NCH₂–} to form a 3D pillared layered structure.