Syntheses, Topological Structures And Properties Of Coordination Polymers Based On Phosphonate And Carboxylate Both Containing Triazole Ring

The chemistry of functional coordination polymers constructed by triazole and its derivatives has been of growing interesting not only due to their high thermal stability and excellent adsorptive property but also for their potential applications in the areas of catalysis, luminescence, magnetism, and so on. In the dissertation, we introduced the phosphonate or carboxylate group into the backbone of the triazole and synthesized three new ligands,2-(1-riazole)-1-hydroxyl-1,1'-ethylidenediphosphonic acid (tahedpH4),2-(1H-1,2,4-triazol)-1-acetic acid monohydrochloride (Htaa) and 2-((1H-1,2,4-triazol-1-yl)methyl)-1H-imidazole-4,5-dicarboxylic acid (H3tmidc). We have obtained 14 novel coordination polymers and especially investigated their topological structures, using solvent-volatilizing and hydrothermal syntheses technology. Their magnetic and fluorescent properties have been studied. The whole dissertation is divided into four chapters.In Chapter 1, the background of this research is primarily introduced. Especially, the application of functional coordination polymers constructed by triazole and its derivatives in the area of adsorption, selective separation and magnetism is analysed by the numbers. The significance and progress of this work is also outlined.In Chapter 2, four novel metal phosphonates, namely, Mn2(tahedp)(H2O)2 (1), Cu2(tahedp)(H2O) (2), Co(tahedpH2) (3) and Ni2(tahedpH2)2·(NH2CH2CH2NH2) (4) have been synthesized by hydrothermal reactions of Mn(Ⅱ), Cu(Ⅱ), Co(Ⅱ) and Ni(Ⅱ) salts with 2-(1-triazole)-1-hydroxyl-1,1'-ethylidenediphosphonic acid. In polymer 1, each tahedp4- ligand is connected to two {Mn12O2} dimer units and three Mn2 centers through Mn-O and Mn-N bonds. Contrarily each {Mn12O2} dimer unit links with four tahedp4- ligands and each Mn2 ion links with three tahedp4- ligands. Topologically, the tahedp4- ligand,{Mn12O2} dimer unit and Mn2 ion can be defined as a 5-,4-and 3-connected node, respectively. On the basis of this simplification, the structure of 1 can be described as an unprecedented trinodal (4.66.83)2(42.62.82)(63)2 topological network. To the best of our knowledge, no metal phosphonates with trinodal (4.66.83)2(42.62.82)(63)2 topology have been reported to date. Topological analysis of polymer 2 reveals that it is a unique 3,4, and 5-connected net with (42.6)2(42.84)(43.6.86)2 topology, where the Cu2 ions,{Cu12O2} dimers and tahedp4-ligands act as 3-,4-and 5-connected nodes, respectively. A better insight into the nature of compound 3 can be achieved by the application of topological analysis. the [CO2O42] dimer unit is defined as a 6-connected node. Similarly, tahedpH22- ligand can act as a 3-connected node. In this structure, the ratio of 3-connected and 6-connected node is 2:1. Consequently, this structure is a binodal net with the Schlafli symbol of (43)2(46.66.83). Polymer 4 exhibits a layer architecture that built from {NiO5N} octahedra interconnected by phosphonate groups and triazole rings. Polymer 4 exhibits a layer architecture that built from {NiO5N} octahedra interconnected by phosphonate groups and triazole rings. The temperature-dependent magnetic susceptibility data of compounds 1-4 indicates a weak antiferromagnetic interaction between the magnetic centers. [Co(aepa)·(4,4'-bpy)·(H2O)2]·2H2O (5) features a 3D alveolate network structure assembling from the intertwist of the six-fold helical chains.In Chapter 3, six novel coordination polymers, namely, [Cd(taa)Cl]n (6),[Hg(taa)Cl]n (7),[Ag1.5(taa)(NO3)0.5]n (8),[Cu(taa)2]n (9) [Cu(taa)2·(H2O)4·Na0.5·(ClO4)0.5]n (10),[Cu(taa)2·(H2O)4·Na0.5·(BF4)0.5]n (11) have been synthesized with 2-(1H-1,2,4-triazol)-1-acetic acid monohydrochloride. In polymer 6, if the [Cd2(CO2)2] unit is considered as a eight-connected node (connecting to six taa- ligands and other two [Cd2(CO2)2] units), the taa- ligand can be considered as a three-connected node (connecting to three bimetallic [Cd2(CO2)2] units), from the topological point of view, the structure can be classified as an unprecedented (3,8)-connected network with the Schlafli symbol (4.52)2(42.58.614.73.8). From a topological view, the formed 3D net of 7 can be best described as a doubly interpenetrated six-connected net with the Schlafli symbol of (410.62.83). Excitation at 380 nm leads to blue fluorescent emission band at 415 nm for the compounds 6-8. The emission can probably be assigned to the intraligand (π-π*) fluorescent emission because the free ligand display fluorescent properties in solid state with the emission maxima being located at 410 nm. Considering that the coordination pattern of Htaa ligand and the other experimental conditions are almost the same in preparing polymers 9-11, we can conclude that the shape, size and charge of ClO4- may be the most important factors in determining the four-fold helical chains in polymer 10-11. A notable structural feature of polymer 10-11 is that it comprises channels formed by the intertwist of the helical chains which are fully filled by the sodium cations and perchlorate anions, respectively. Two novel coordination polymers, namely, [Co1.5(tmidc)(H2O)4]n (13)和[Zn(Htmidc)]n (14) have been synthesized with 2-((1H-1,2,4-triazol-1-yl)methyl)-1H-imidazole-4,5-dicarboxylic acid by the means of hydrothermal technique. In polymer 13, two neighboring Co2 ions are fused together forming a [Co2(tmidc3-)3] dimeric unit. These [Co2(tmidc3-)3] dimeric units are connected along the direction of c axis to form a four-fold infinite helical chain. The channels having square section are formed by the intertwist of these helical chains.In Chapter 4, conclusion of this work is given.