Synthesis, crystal structure, and thermal stability of a novel 3D cadmium carboxyphosphonate containing left-hand helical chains Cd3Cl2[(O3PCH2–N(H)C5H9–COO)2(H2O)2] · 4H2O

A novel 3D cadmium carboxyphosphonate containing left-hand helical chains, Cd3Cl2[(O3PCH2–N(H)C5H9–COO)2(H2O)2] · 4H2O 1 has been synthesized by hydrothermal reaction at 120 °C and structurally characterized by single-crystal X-ray diffraction as well as with infrared spectroscopy, elemental analysis and thermogravimetric analysis. In compound 1, the hexanuclear clusters based on Cd(1)O4Cl2, Cd(2)O4Cl2, Cd(3)O6 and CPO3 polyhedra are interconnected through carboxyphosphonate ligands to form a 3D open-framework structure with channel system. The result of connections in this manner is the formation of 20- and 30-atom rings that are parallel to one another and run in the a-axis direction. It is interesting that a type of left-hand helical chain is formed by HL2− ligands bridging Cd3 ions running along the b-axis.