Syntheses, Crystal Structures And Properties Of Transition Metal Coordination Polymers Based On Benxotriazole-5-carboxylate Ligand

Ditopic ligands containing carboxylic and nitrogen donor groups have been widely used to architect novel coordination polymers. These complexes possess potential applications in gas storage, adsorption based gas/vapor separation, shape/size-selective catalysis, drug storage and delivery, optical, electrical and magnetism properties. We mainly introduce the construction of the novel and multifunctional complexes based on benzotriazole-5-carboxylate acid (H2btca) under hydro-(solvo-) thermal reaction. This thesis is divided into five chapters.In chapter 1, the research background is concisely introduced with emphasis on the current survey in the area of coordination polymers. Some special structures and multifunctional coordination polymers are mainly summarized. The history and actuality of some notable compounds based on ligands contained different characteristics of the groups are briefly reviewed. In addition, the intention and significance of coordination polymers based on benzotriazole-5-carboxylate acid are also elucidated.In chapter 2, we report the syntheses of three novel coordination complexes by reactions of transition metal ions with H2btca under hydro(solvo)thermal reaction conditions, [Cu(btca)(H₂O₂] (1), [Cu(btca)(H₂O)3.5]·H₂O (2), [Cu_2.5(btca)(H_0.5btca)(μ2-Cl)_0.5(μ3-OH)(H₂O)]·H₂O (3). Compound 1 is two dimensional (2D) network. And compound 2 represents the first example of a neutral flattened metallomacrocycle-based hydrogen-bonded nanotubular structure. Nevertheless, compound 3 is a 3D metal-organic framework encompassing a considerable solvent-accessible volume with 1D honeycomb channels. Detailed magnetic measurement exhibits anti-ferromagnetic behavior of 1² and weak ferromagnetic behavior at low temperature of 3 .In chapter 3, [Zn(btca)(H₂O)] (4), [Zn(btca)(H₂O)]·_2.5H₂O (5), [Zn3(btca₂(μ3-OH₂]·DMF·4H₂O (6) have been self-assembled with transition metal ions Zn(II) and H2btca ligand. It is noteworthy that 4 and 5 are pseudo-supramolecular isomers, which are produced from the influence of water. Besides, Compound 6 exhibits great flexibility (the so-called"breathing") which has obvious variation in unit cell volume by heating. All of the materials exhibit intense fluorescent emission wherein 6 presents interesting guest-dependent photoluminescent property. What's more, this multifunctional material combined with flexible porosity and intense photoluminescence is very rare.Chapter 4 focuses on reactions of H2btca ligand and cadmium ions Cd(II), which indicates that metal ions and solvents take essential role on these structures of the three complexes as followed: [Cd(Hbtca)₂] (7), [Cd(btca)(H₂O)₂] (8), [Cd(btca)] (9). The results indicate that the ligand is deprotonated to form different anionic derivatives in the obtained complexes. Compound 7 features three-fold interpenetrated net with diamond-like topology. 8 and 9 exhibit diverse superstructures, one dimensional (1D) chain, 3D close-grained network, respectively. In addition, these complexes exhibit fluorescence emissions.Finally, the main achievements and conclusions in this thesis are summarized. The further research plan in this project has also been proposed.