| Exploiting a desirable strategy to design and synthesize high-performance molecular-based magnets has already attracted plenty of attention. In this thesis, focusing on solvent effects in the construction of coordination polymers, in consideration of azido anion possessing the remarkable abilities of coordination and magnetic transmission, the coordination compounds of Cu-N3- have been synthesized with rigid aromatic-ring substituted benzoic acids as coligands. The as-prepared compounds have been structurally and magnetically characterized in detail, the regulatory mechanism derived from solvent effects on the structures and magnetisms of azdio-Cu(Ⅱ) compounds has been discussed. Systematic investigations provide theoretical and practical experience for the preparation of superior molecular-based magnets.1. A new azido-Cu(Ⅱ) compound, [Cu(4-fba)(N3)(C2H5OH)] (4-fba= 4-fluorobenzoic acid) (1), has been synthesized and characterized. X-ray crystal structure analysis determines that only one crystallographically independent Cu(Ⅱ) ion in the asymmetric unit of 1 exhibits a stretched octahedral geometry where two azido N atoms and two carboxylic O atoms locate at the equatorial square, while two ethanol O atoms occupy the apical positions. Cu(Ⅱ) ions are inked into forming a 1D Cu(Ⅱ) chain with alternating triple-bridge of EO-azido, syn, syn-carboxylate and μ2-ethanol. The title compound consists of ferromagnetically interacting ferromagnetic chains exhibiting a ferromagnetic order (Tc= 7.0 K). The strong ferromagnetic coupling between adjacent intrachain Cu(Ⅱ) ions is due to the countercomplementarity of the super-exchange pathways whereas the ferromagnetic interchain interactions-responsible for the long-range magnetic ordering-are most likely due to the coordinated ethanol molecules resulting in hydrogen bonds with neighboring chains. DFT calculations have been performed on the compound 1 to offer a qualitatively theoretical explanation of the magnetic behavior.2. Three new azido-copper coordination polymers, [Cu(2-na)(N3)] (2), [Cu(2-na)(N3)] (3) and [Cu(2-na)(N3)(C2H5OH)](4) (2-na= 2-naphthoic acid), have been successfully prepared. Structure analysis shows that the Cu(II) cations in compounds 2-4 present tetra-, penta-and hexa-coordination geometries, respectively. Compound 2 is a well-isolated 1D chain with EO-azido group, while the isomers of 2 and 3 exhibit 2D layer-structure involving EE-azido group. Thermodynamically, DFT calculation reveals that 2 locates in the metastable state and 3 occupies the stable state. Compound 4 consists of a 1D chain with triple bridging mode, which is derived from 2 undergoes a single-crystal-to-single-crystal transformation through soaking in ethanol solvent, and the powder product of 2, namely 2b, could be yielded from the dealcoholization of compound 4. Magnetic measurements indicate that compounds 2-4 perform strong intrachain ferromagnetic interactions, experiencing long-range magnetic ordering and slow magnetic relaxation. Compound 2 features the metamagnetic behavior with transition temperature of 15 K, while 3 and 4 display spin glass behavior with the phase transition temperatures of 15 and 12 K, respectively. Magneto-structure relationships are investigated as well.3. Employing CF3 substituted benzoate as coligand, four novel azido-copper compounds, [Cu4(4-tfmba)4(N3)3(OH)] (5), [Cu(4-tfmba)(N3)(CH3OH)] (6), [Cu(4-tfmba)(N3)(C2H5OH)] (7) and [Cu(4-tfmba)(N3)(C3H7OH)] (8) (4-tfmba= 4-Trifluoromethyl-benzoic acid), have been successfully prepared in various solvents. Single-crystal structure analyses demonstrate that compound 5 includes μ3-hydroxy, (u2-O,O’) (μ3-O,O,O’) carboxylate and （μ-1,1) (μ-1,1,3) azido mixed-bridged fashions, exhibiting an unusual 2D azido-copper system consisted of tetranuclear Cu(Ⅱ) unit. Compound 6-8 present similar 1D chain structure, which possesses threefold bridging ligands, one μ-1,1-azido, one (syn-syn) 4-tfmba and one ethanol molecule. Magnetic measurements indicate that all compounds exhibit strong ferromagnetic feature. Intricate bridges between adjacent Cu(Ⅱ) ions lead to complicated magnetic behaviors in compound 5.6-8 display slow magnetization relaxation with different relaxation time resulting from diverse alcohol solvents coordination.4. In methanol solvent, two new azido-Cu(Ⅱ) coordination polymers, [Cu(4-NBA)(N3)(CH3OH)] (9) and [Cu(3,5-DNBA)(N3)] (10), have been synthesized and structurally characterized by single crystal X-ray diffraction, where 4-NBA and 3,5-DNBA represent 4-nitrobenzoic acid and 3,5-dinitrobenzoic acid, respectively. X-ray crystal structure analysis determines that compound 9 exhibits 1D Cu(Ⅱ) chain structure with alternating triple-bridge of EO-azido, syn,syn-carboxylate and μ2-methanol. In compound 9, The interchain hydrogen-bonding between the oxygen atom in nitro group and the methanol oxygen atom integrates all of the Cu(Ⅱ) chains, constructing the supramolecular framework. For 10, the central Cu(Ⅱ) ion coordinates with two azide anions and three 3,5-dinitrobenzoic acid anions to form a five-coordinated tetragonal pyramid structure. Noteworthily, one oxygen atom in nitro group displays rare coordination to Cu(Ⅱ) ions in known complexes. Two compounds exhibit intrachain ferromagnetic and interchain afferromagnetic exchanges. As observed, compound 10 shows an abrupt thermal decomposition at 268 ℃, representing explosive performance and superior thermostability. The compound is insensitive to external stimuli. In addition, the kinetic parameters of the exothermic process and the standard molar enthalpy of formation are calculated.In summary, the present work presents a fine-tuning example for the structures and magnetisms of Cu(Ⅱ)-N3- coordination compounds through solvent effects and promote the investigation of azido-Cu(Ⅱ) system, which provides theoretical foundation for the directed synthesis and magnetic exploration of azido-Cu(Ⅱ) compounds.
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