| Coordination polymers are of increasing interest not only due to their incomparable aesthetic characteristics, but also because of their potential applications, such as magnetism, gas adsorption, ion recognition, catalysis, optical storage and so on, among which, the study about their magnetic property and ion recognition is the most sought-after. So this paper focuses on these two hotpots. First, we successfully realized the construction of molecular magnet structures and regulation of properties through the ultilization of secondary building units (SBUs); second, we successfully completed the recogniton of Cu2+and various anions.The main contents of this thesis are as follows:1. In order to regulate the perperties of metal organic complexes, we assembled flexible tri-carboxylate ligand with Mn(OAc)2, with the help of N-donor auxiliary Ligands, obtained a series of high-dimensional polymers, which were based on mononuclear, dinuclear, tetranuclear, hetanuclear, uniform chain and alternating chains. Then we studied their magneto-structural correlations and found that secondary building units were the main factors for influencing magnetic interactions. Compound4showed a very rare (3,12)-connected structure. Complex6and7contained unprecedent infinite alternating Mn chains. The arrangement mode of the chain is J1J2J3J1, which is rare.2. In order to realize the prediction and regulation of metal-organic framework structure, we tried to explore the effects of solvent, pH values and auxiliary ligands on the structures of products. Initially, by changing the solvents, four Zn polymers with different SBUs were synthesized. Then, by changing auxiliary ligands, we obtained another four different structural Zn complexes. Finally, by changing pH values, we synthesized two different Zn polymers. The SBU of complex11is built by an infinite rod-shaped metal cluster chain. The sequence of Zn ions in the chain is rare and complex. Complex12had two kinds of left-and right-helical chains. Compound13possessesd a (3,10)-connected topology.3. In order to realize structure regulation of metal-organic framework, we intended to synthesize porous magnet with infinite alternating copper chains, and we finally acquired the target products. Complexes19-22included infinite alternating chains. The arrangement of the chains is ABBA mode. But there are minor differences between the chains, and it is the different distances betweent Cu ions that cause the final different structures. We also studied their magnetism. By fitting the magnetic data, we found that all of them are antiferromagnets.4. In order to explore MOFs for recognizing ions and anions, the crystals of a known Cd-MOF (23) were immersed into several kinds of solutions containing different metal ions. The MOF only showed the rapid identification for Cu2+. Then to test whether the types of anions influence Cu2+identification or not, we soaked the crystals into Cu(NO3)2, CuBr2, CuCl2solution and found that anions did not influence Cu2+recognition for Cu2+. When the crystals underwent the whole process of adsorption, dissolution and recrystallization, three new crystals were obtained. Through X-ray single crystal analysis, we found that the three crystals own different structures. So the complex23also achieved the recognition for three kinds of anions from the other side. As well known, Cu2+and I-ions cannot coexist, but we found that there were I3-arranged as a Zigzag chain existing in the cavity of Cu-MOF (24). Then, in order to explore anion recognition, we first synthesized a new Cu-MOF (27), and soaked the crystals of24into several kinds of solutions with different anions. The crystals displayed different colors in different solutions. IR, elemental analysis, single crystal characterization proved that this process was a single crystal to single crystal transformation. When complex27were immersed in KI solution, we also obtained a cupric iodide polymer (28). |
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