Synthese, Structure And Properties Of Metal Coordination Polymers With Bipyridine Polycarboxylate

In recent years, coordination polymers have been one of the most attractive areas in coordination chemistry and material science because of their interesting structures and spectroscopic, luminescence, catalytic, magnetic properties and host-guest chemistry. Metal complexes with pyridinepolycarboxylate and bipyridinepolycarboxylate ligands have been recently thoroughly investigated. They can form 1D,2D or 3D networks and polynuclear complexes owing to the ligand coordination via N and O atoms and due to the formation of hydrogen bonds. The aim of this paper is to construct the coordination polymer through the self-assembly by oxygen and nitrogen donors of multidentate ligands with lanthanide and/or transition metal ions in hydrothermal reaction. We report 2,2'-bipyridine-3,3',6,6'-tetracarboxylic acid (H4bptc),2,2'-bipyridine-3,3'-dicarboxylate and seven new coordination polymers, namely, [Nd(Hbptc)(H₂O)₂]·H₂O(1), [Mn(H₂bptc)(H₂O)](2), [Zn2(H₂bptc)₂(H₂O4]·(H₂O)₄(3), [Cd(H₂bptc)(H₂O)₂]·(H₂O)₂(4), [Cu4(H₂bptc)₄(H₂O)₄](H₂O)9(5), [Cu2(2,2',6,6'-bpdc)₂(H₂O)₂]-H₂O(6), [Ag2(2,2',3,3'-bpdc)(H₂O)0.5]·(H₂O)1.5(7). In this paper, totally 7 different structures have been obtained, and characterized by X-ray, IR, TGA-DTA, luminescence and magnetism.Compound 7 exhibits a complex 3D framework, compound 2 exhibits a complex 3D framework containing 2D network by hydrogen bonds. Compound 1 and 4 exhibit an infinite 2D network containing 1D channels occupied by hydrogen bonds. Compound 3, 4,5 are all dinuclear complexes, they exhibit 1D network by hydrogen bonds. Compound 1,3,4 display fluorescent emissions in the solid state, compound 1 displays (?)ear-IR emission of Nd(â…¢) ions by 4F3/2→4I11/2, the fluorescent emissions of compound 3,4 all can be assigned to intraligandÏ€-Ï€* transitions. Compound 2 shows an antiferromagnetic interaction between Mn2+.The different structures in compound 5 and have been obtained through the same ligand by different synthetic procedures.