Metal Coordination Polymers Of The Organic Phosphonic Acid Synthesis, Characterization And Crystal Structure Study

Metal phosphonate coordination polymers have attracted a great deal of research interest due to their structural diversities and many potential and practical applications in catalysis, ion exchange, intercalation chemistry, absorption, proton conduction, and so on.In this work, we have devoted effort toward hydrothermal synthesis of the metal-organic coordination polymers by using organophosphonic acid ligands RPO₃H₂ (R = chiral or achiral organic groups with functional groups such as -OH, -NH₂ and -COOH ) with chiral groups as chiral building units to obtain possible new types of materials with potential applications. Eight novel metal phosphonate coordination polymers were hydrothermally synthesized by using direct reaction or organic-amine as template agent, and characterized by using X-ray single-crystal diffraction, IR spectroscopy and thermogravimetric analysis.Three kinds of organophosphonic acid ligands, such as a-aminoethylphosphonic acid, (S)-proline-N-methyl- phosphonic acid and 2-hydroxyphosphonoacetic acid were used in the synthesis of metal phosphonate coordination polymers. In the structure of these compounds, the MO_n (M = metal, n = the number of oxygen atoms) polyhedral are bridged by the oxygen atoms from the functional groups of the organophosphonic acid ligands, resulting in the formation of two-dimensional layer or three-dimensional open framework. The chemical constitution formulas are listed as follow: Zn[O₃PCH(NH₂)CH₃]·2H₂O (1) Pb₄O[O₃PCH₂-NC₄H₇-CO₂]₂ (2), Mg_0.5Cd[O₃PCH(OH)CO₂] (3), Na₂[Cd₂(H₂O)₃(O₃PCH-(OH)CO₂)₂]-2H₂O (4) , NaCo[O₃PCH(OH)CO₂] (5) , NaMn[O₃PCH(OH)CO₂] (6) , [NH₃CH₂CH₂NH₃][Fe₂(O₃PCH(OH)CO₂)₂(H₂O)₂]-2H₂O (7) and [NH₂CH₂CH2NH₂][Sb₂-{O₃PCH(OH)CO₂}₂] (8) . Compounds (1) (6) are obtained by the direct reaction, and the single-crystal X-ray diffraction analysis shows that the compounds (5) and (6) feature three-dimensional open framework structure, and the other four compounds form two-dimensional layer structure. Compounds (7) and (8) are synthesized by using organic-amine as template agent, X-ray diffraction analysis shows that the two compounds feature two-dimensional layer structure, and the ethylenediamine cations are located in the...