Syntheses, Crystal Structures And Properties Of Coordination Polymers Constructed From 2-hydroxyquinoline-4-carboxylic Acid And 1H-1,2,3-triazole-4,5-dicarboxylic Acid.

The coordination polymers not only have abundant topological structures but also have widely promising applications in the field of catalysis, molecular conductor, luminescent materials, molecular magnet and nonlinear optics. Some studies indicate that the coordination properties of organic ligands and metal ions exert a crucial influence on the structure and function of coordination polymers, and other factors such as anion, template, mol ratio of reactant and pH value of reaction system play an role in synergistically regulate and control the reaction. So, chemists have been pursuing to design and synthesize the expected structures of coordination polymers with excellent properties. Recently, people have synthesized a lot of metal-organic coordination polymers with novel topological structure by using N-heterocyclic carboxylic acid ligands. In this paper, we have successfully constructed seventeen compounds by employing 2-hydroxyquinoline-4-carboxylic acid (H2hqc) and 1,2,3-triazole-4,5-dicarboxylic acid (H3tda) as main ligands and using some other accessorial ligands with Zn²⁺, Cd²⁺ transition metal ions and rare-earth metal ions under hydrothermal or solvent conditions. We character the crystal structures and the the fluorescence properties of the compounds, as well as survey the influence of the confirmations of ligands and metal cations on the structures of the compounds.1. We have successfully synthesized two novel compounds, [Zn₅(hqc)₄(μ3-OH)₂]_n (1) and [Ni(hqc)₂(H₂O)₂] (2), by employing 2-hydroxyquinoline-4-carboxylic acid as ligand with Zn²⁺ and Ni²⁺ transition metal ions with hydrothermal or solvent method. We discuss the coordination geometry of metal ions and the influence of reaction conditions on the structure of products. At last, we also investigate the luminescent properties of compounds.2. We have successfully constructed eight new compounds by using 1,2,3-triazole-4,5-dicarboxylic acid as the first ligand and using the neutral containing nitrogen organic molecular such as 2,2′-bipy as the second ligand with transition metal ions such as Zn²⁺, Ni²⁺, Co²⁺, Pb²⁺ under the hydrothermal conditions. {[Cd₃(tda)₂(pyim)₃]·3H₂O}_n (7) is a one-dimensional structure, {[Zn₃(tda)₂(bipy)₂(H₂O)₂]·4H₂O}_n (3) and {[Cd₃(tda)₂(bipy)₃]·5H₂O}_n (4) are two-dimensional layer structures. [Zn₂(tda)(tz)(H₂O)₂]·H₂O (5), [Zn₂(tda)(tz)(H₂O)₂]·H₂O (6), [Cd₇(tda)₄(pz)(Ac)(H₂O)₇]·3H₂O (8), [Co₅(tda)₄(H₂O)₈]_n (9), and [Pb(tda)]n (10) are three-dimensional structures. We discuss the coordination geometry of metal ions, the coordination modes of ligands and the influence of the second ligands on the structures and investigate the luminescent properties of compounds.3. We obtain 7 isomorphic chiral metal-organic coordination polymers, [Ln(tda)(H₂O)]·2H₂O (Ln = La(11), Ce(12), Pr(13), Nd(14), Eu(15), Sm(16), Gd(17)), by using 1,2,3-triazole-4,5-dicarboxylic acid as ligands with lanthanide metal ions. We discuss the chiral characteristic of these complexes and investigate the luminescent properties and magnetic properties of them.