| In this thesis, eleven complexes were synthesized by reactions 8-quinolinolate ligands or 2,6-diacetylpyridine with lanthanide（III） ions, and their structures were studied. The magnetic measurements reveal that five of them display Single-Molecule magnetic behavior in zero field. Through tuning molecule symmetry by modulating the coordination environments of centre lanthanide（III） ions to control the ligand field, and study the correlations between single-molecule magnetic behaviour and structure.The main contents include the follows:1. A series of tetranuclear complexes with D4 d symmetry cores were designed and synthesized by 8-quinolinolate ligands and Dy（III） ions, their structures were determined, being with the follow formulas: [{Dy（q）2（acac）}2（u3-OH）2{Dy（q）（acac）}2]·（CH2Cl2）2（1）,[{Dy（q）2（TMHD）}2（u3-OH）2{Dy（q）（TMHD）}2]·（CHCl3）3（2）, [{Dy（q）2（DBM）}2（u3-OH）2{Dy（q）（DBM）}2]·（CH2Cl2）5（3）,[{Y（q）2（DBM）}2（u3-OH）2{Dy（q）（DBM）}2]·（CH2Cl2）6（4）,[{Dy（q）2（DBM）}2（u3-OH）2{Y（q）（DBM）}2]·（CH2Cl2）3（5）, [{Dy（q）2（hfac）}2（u3-OH）2{Dy（q）（hfac）}2]·CHCl3（6）, magnetism studied reveal that five of them show the typical single-molecule magnetic behaviour.2. A series of mononuclear and dinuclear complexes with D5 h symmetry cores constructed by L1 and L2 ligands（L1 = 8-hydroxyquinoline-2-formaldehydesemicarbazide, L2 = 8-hydroxyquinoline-2-formaldehyde-benzoyl hydrazine） with Dy（III） and Er（III） ions. [L1Dy Cl3]·CH3OH（7）, [L1Er Cl3]·CH3OH（8）, and [（L2）2Dy2Cl2]·CH3CN（9） were designed and synthesized, and their structures were measured. The magnetism studied indicate a slow magnetic relaxation in comliex（7） and（8） under nonzero magnetic fields.3. Two mononuclear complexes（[（L3）2（L4）2Dy（OAc）2Cl]·3H2O（10）, {[（L3）2（L4）2Er（OAc）2Cl]}2·2H2O（11）） were designed and synthesized by 2,6-diacetylpyridine-ethylenediamine with Dy（III） and Er（III） ions. And their structures and magnetic properties were measured. Complex（10） shows a slow magnetic relaxation by applying an external magnetic field, and complex（11） shows a typical single-molecule magnetic behaviour under optimum static dc field of 700 Oe. |
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