Synthesis, Crystal Structures And Properties Of Metal Phosphonate Coordination Polymers With Functional Groups

In recent years, metal phosphonates have been attracted a lot of research attentions due to potential applications in the areas of catalysis, ion exchange, proton conductivity, intercalation chemistry, photochemistry, and materials chemistry. The strategy of attaching functional groups such as carboxylate, amine, hydroxyl, and crown ether groups to the phosphonic acid has become a rational synthetic route for the designing of new functional materials based on metal phosphonates.In this paper we synthesized three phosphonic acid and phosphonate ligands as follows: N-morpholinomethylphosphonic acid, N–(diethanolamine)methylenephosp- honic acid and N, N–butylamine bis(methylenephosphonic acid). We have devoted effort toward hydrothermal synthesis of metal phosphonate coordination polymers by using the above three phosphonic acids and one water treatment agent 1-hydroxyethylidenediphosphonic acid (hedpH4) as ligand.Twenty novel metal phosphonate coordination polymers are hydrothermally synthesized by using direct reaction, organic-amine as template agent or oxalate as the second metal linker, and characterized by using X-ray single–crystal diffraction, IR spectroscopy and thermogravimetric analysis. Meanwhile, the luminescent properties of compounds 9 and 11 have also been studied. The chemical constitution formulas are listed as follow: (1) Zn₂Cl[O₃PCH₂N(CH₂CH₂)₂O][O₃PCH₂NH(CH₂CH₂)₂O] (2) Pb₂Cl₃[O₃PCH₂NH(CH₂CH₂)₂O]·2.5H₂O (3) [La{O₃PCH₂NH(CH₂CH₂)₂O}(C₂O₄)]·H₂O (4) [Y₂{HO₃PCH₂NH(CH₂CH₂)₂O}(C₂O₄)₃(H₂O)₃]·H₂O (5) [Ce₃{O₃PCH₂NH(CH₂CH₂)₂O}(C₂O₄)4(H₂O)4]·2H₂O (6) [Pr₃{O₃PCH₂NH(CH₂CH₂)₂O}(C₂O₄)4(H₂O)4]·2H₂O (7) [Nd₃{O₃PCH₂NH(CH₂CH₂)₂O}(C₂O₄)4(H₂O)4]·2H₂O (8) [Sm₃{O₃PCH₂NH(CH₂CH₂)₂O}(C₂O₄)4(H₂O)4]·2H₂O (9) [Eu₂{HO₃PCH₂NH(CH₂CH₂)₂O}(C₂O₄)₃(H₂O)₃]·H₂O (10) [Gd₂{HO₃PCH₂NH(CH₂CH₂)₂O}(C₂O₄)₃(H₂O)₃]·H₂O (11) [Tb₂{HO₃PCH₂NH(CH₂CH₂)₂O}(C₂O₄)₃(H₂O)₃]·H₂O (12) [Dy₂{HO₃PCH₂NH(CH₂CH₂)₂O}(C₂O₄)₃(H₂O)₃]·H₂O (13) [NH₃(CH₂)₄NH₃]Sm[hedpH][hedpH₂] (14) [NH₃(CH₂)₄NH₃]Gd[hedpH][hedpH₂] (15) [NH₃(CH₂)₄NH₃]Dy[hedpH][hedpH₂] (16) [NH₃CH₂CH₂NH₃][Zn₃(hedp)₂(H₂O)]·H₂O (17) [NH₃CH₂CH(CH₃)NH₃][Zn₃(hedp)₂(H₂O)]·3H₂O (18) [Cu₂(hedp)(H₂O)₂]·0.5H₂O (19) Cd₂[{O₃PCH₂N(CH₂CH₂O)₂}(H₂O)₂] (20) Mn₂[CH₃(CH₂)₃NH(CH₂PO₃)₂(H₂O)F]·2H₂OCompounds 1–12 are obtained by using N-morpholinomethylphosphonic acid as the phosphonate ligands and by the direct reaction or by oxalate as the second metal linker. X-ray diffraction analysis shows that the compounds 1–3 are two-dimensional layered structure, and compounds 5–12 feature three-dimensional open-framework structure. Compounds 13–18 are synthesized by using 1-hydroxyethylidenediphosphonic acid (hedpH4) as the phosphonate ligands and by using organic-amine as template agent or by the direct reaction. X-ray diffraction analysis shows that the compounds 13–15 are one-dimensional chain structure, compounds 16 and 17 are two-dimensional layered structure, and compounds 18 feature a three-dimensional open-framework structure. Compounds 19 is obtained by N–(diethanolamine)methylenephosphonic acid and by the direct reaction, compounds 20 is synthesized by N, N–butylamine bis(methylenephosphonic acid) and by the direct reaction. X-ray diffraction analysis shows compounds 19–20 are two-dimensional layered structure.The thermal behaviors of the twenty compounds have been investigated by using the TG-DTA analysis, which indicated that these compounds form the stabilized framework structure. Compounds 9 and 11 show strong red and green fluorescent emissions, respectively, in the solid state at room temperature.