分子基磁体的合成、表征及性质研究毕业论文
2022-01-09 21:43:58
论文总字数:22759字
摘 要
在高密度信息存储、磁热开关、温度传感、显示、导电、能源等领域,分子基功能材料具有应用价值。过渡金属双-(马来二腈基二硫烯)阴离子是构筑分子基磁性材料的重要结构单元。在本论文中,本人将磁性[Ni(mnt)2]-阴离子和平衡阳离子[CH3-Bz-DABCO] 作为分子构筑单元组装成配合物[CH3-Bz-DABCO ][Ni(mnt)2],并对配合物作元素分析,SC-XRD、PXRD、TG、DSC、变温磁化率等基本表征,探究其结构特征以及相关性质。晶体结构数据表明配合物[CH3-Bz-DABCO ][Ni(mnt)2]属于三斜晶系,空间群为P-1,晶体的不对称单元包含一个[CH3-Bz-DABCO] 阳离子和一个平面型的[Ni(mnt)2]-阴离子。晶胞参数a = 7.2757(14) Å,b = 12.696(2) Å, c = 14.4400(19) Å,α = 71.030(6)°,β = 80.849(6)°,γ = 75.286(7)°,V = 1215.8(4) Å3。元素分析和X射线粉末衍射谱表明所制备的配合物具有很高的相纯度。热重分析表明配合物在240℃以前处于稳定未分解状态。DSC曲线图表明配合物在64.3℃有微小的异常峰,可能存在相变。配合物在低温下表现出弱的居里-外斯顺磁行为,此外在215K时配合物由抗磁性变为顺磁性。
关键词:分子基磁性材料 [Ni(mnt)2]- 晶体结构 磁学性质
ABSTRACT
In the fields of high density information storage, magnetocaloric switches, temperature sensing, display, electrical conduction, energy, etc,molecular-based functional materials have application value. Bis-1,2-dithiolene complexes of transition metals anion is an important structural unit for building molecular- based magnetic materials. In this paper, complex [CH3-Bz-DABCO][Ni(mnt)2] was prepared with a magnetic [Ni(mnt)2]- anion and an equilibrium cation [CH3-Bz-DABCO] . Then, the complex of [CH3-Bz-DABCO][Ni(mnt)2] was characterized by using PXRD, TG, DSC, magnetic susceptibility, etc., and analyzed in structure, composition and properties. Crystal structure analysis data shows that the complex of [CH3-Bz-DABCO][Ni(mnt)2] belongs to triclinic crystal system, the space group is P-1. Meanwhile, a [Ni(mnt)2]- anion and a [CH3-Bz-DABCO] cation was included in the asymmetric unit of the crystal. Unit cell parameters a=7.2757(14)Å, b=12.696(2)Å, c=14.4400(19)Å, α=71.030(6)°, β=80.849(6)°, γ=75.286(7)°, V=1215.8(4)Å3. X-Ray powder diffraction spectrum and Elemental analysis indicated that the prepared complex of [CH3-Bz-DABCO][Ni(mnt)2] has high phase purity. Thermogravimetric analysis showed that the complex was in a stable undecomposed state before 240°C. The DSC curve shows that the complex we prepared has an insignificant abnormal peak at 64.3℃, and there may be a phase transition. The complex exhibits weak Curie-Weiss paramagnetic behavior at low temperature, and at 215K, the complex changes from diamagnetic to paramagnetic.
Key Words:Molecular-based magnetic materials; [Ni(mnt)2]- ; Crystal structure; Magnetic properties
目 录
摘要 I
ABSTRACT II
第一章 绪论 1
1.1 分子基磁性材料 1
1.1.1 分子基材料的研究背景及意义 1
1.1.2 分子基磁性材料的发展历程 1
1.1.3 多功能分子基磁性材料 1
1.2 过渡金属二硫烯配合物体系 3
1.2.1 过渡金属二硫烯配合物的结构特征 3
1.2.2 过渡金属二硫烯配合物的光、电、磁性质 4
1.2.3 过渡金属二硫烯配合物的发展历程 6
第二章 实验 8
2.1 试剂和原料 8
2.2 配合物合成 8
2.2.1 合成(CH3-Bz-DABCO)Cl 8
2.2.2 合成[(CH3-Bz-DABCO)]2[Ni(mnt)2] 8
2.2.3 合成[(CH3-Bz-DABCO)][Ni(mnt)2] 9
2.2.4 培养单晶 9
2.3 仪器及测试条件 9
第三章 数据分析与结果讨论 11
3.1 元素分析 11
3.2 X射线粉末衍射谱 11
3.3 晶体结构描述 12
3.4 热重分析 16
3.5 差式扫描量热分析 17
3.6 磁学性质研究 18
第四章 结论与展望 19
4.1 结论 19
4.2 展望 19
参考文献 20
致谢 22
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