节点文献
热爆法制备纳米氧化物及其稀土配合物晶体培养
Preparation of Nanometer-scale Oxides by Thermo-decomposition and Synthesis of Lanthanide Complex Crystals
【作者】 赵丽芳;
【导师】 陈亚芍;
【作者基本信息】 陕西师范大学 , 物理化学, 2007, 硕士
【摘要】 随着科学研究的深入和发展,纳米材料引起了人们广泛的兴趣,并且得到了迅速发展。由于其具有表面效应、体积效应、量子尺寸效应和宏观量子隧道效应,因而具有各种奇异的力、电、光、磁、热效应以及化学活性。其中纳米稀土氧化物更是具有传统固体不具有的许多特殊性质和用途,例如氧化钕等。本文报道了通过配合物简单的热分解得到高纯度的纳米级氧化铁和氧化钕的方法,并对所制得的纳米级氧化铁和氧化钕的性质进行了表征。进一步针对稀土氧化物制备过程的中间体配合物,在一定的条件下得到了单晶,并对得到的晶体的性质进行了表征。(1)纳米级氧化铁和氧化钕的制备与表征。以邻硝基苯甲酸和铁的硝酸盐为原料,调节pH值使之产生相应的沉淀,以一定的温度焙烧此沉淀,可得到高纯度纳米氧化铁。讨论了不同焙烧温度对纳米氧化铁粒度和比表面积的影响。通过透射电子显微镜(TEM)观察,所制得的纳米氧化铁尺寸在10~45nm范围内,并且分散性很好。通过X-射线衍射(XRD)和比表面积测定(BET)的表征也进一步证明了此纳米粒子的尺寸。同时,XRD表征结果显示,此法制备的纳米氧化铁的纯度较高。通过比表面积测定得知,纳米氧化铁的比表面积可以达到65.44 m2·g-1。实验还得出,加入阴离子表面活性剂在纳米级氧化铁的制备中起到了非常重要的作用,并对其影响做了讨论。以邻硝基苯甲酸和钕的硝酸盐为原料,调节pH值使之产生相应的沉淀,以一定的温度焙烧此沉淀,可得到纳米级氧化钕。通过TEM观察,所制得的纳米稀土氧化钕尺寸在20~40mm范围内,并且分散性很好,而且随着焙烧温度的升高粒子的粒径变大。(2)稀土配合物[Nd(o-NO2-C6H4COO)3(DMF)2]2和[In(o-NO2-C6H4COO)3(DMF)2]2(Ln=Ce,Sm)的制备与表征。合成了两种新的双核倒反中心的稀土配合物[Nd(o-NO2-C6H4COO)3(DMF)2]2和[Ln(o-NO2-C6H4COO)3(DMF)2]2(Ln=Ce,Sm)。通过元素分析(EA)和傅立叶红外光谱(FT-IR)对配合物进行了表征,利用热重分析(TGA)研究了配合物的热稳定性,用X射线单晶衍射法(SCXRD)测定了其晶体结构。钕配合物[Nd(o-NO2-C6H4COO)3(DMF)2]2晶体属三斜晶系,空间群P-1,晶胞参数a=1.18652(12)mm,b=1.24784(13)nm,c=1.29958(13)nm,α=64.220(1)°,β=66.306(1)°,γ=71.825(1)°,V=1.5645(3)nm3,Dc=2.167 mg·m-1,Z=2,μ=3.415 mm-1,F(000)=986。配合物中每个Nd(Щ)被4个邻硝基苯甲酸根桥联,Nd(Щ)的配位数为8,配位原子分别来自于5个邻硝基苯甲酸羧酸根的6个氧原子和2个DMF的羰基氧原子。配合物中的氢键和π…π堆积作用使其成为三维立体结构。同时发现了标题配合物固体具有光致发光现象,发光性能测试表明该配合物具有很好的荧光性质。稀土铈和钐配合物[Ln(o-NO2-C6H4COO)3(DMF)2]2(Ln-Ce,Sm)晶体属三斜晶系,空间群P-1,晶胞参数a=1.18284(6)nm,b=1.25082(7)nm,C=1.30203(7)nm,α=63.965(10)°,β=66.390(10)°,γ=71.738(10)°,V=1.5637(14)nm3,Dc=1.688 mg·m-1,Z=2,μ=1.954 mm-1,F(000)=794。配合物中每个In(Щ)被4个邻硝基苯甲酸根桥联,Ln(Щ)的配位数为8,配位原子分别来自于5个邻硝基苯甲酸羧酸根的6个氧原子和2个DMF的羰基氧原子。配合物中的氢键和π…π堆积作用使其成为三维立体结构。同时发现了标题配合物固体具有光致发光现象,发光性能测试表明该配合物具有很好的荧光性质。
【Abstract】 With the development of science research, nanometer scale materials have recently attracted a lot of research interests and developed very rapidly. Nanometer scale materials have unique properties, such as force, electricity, light, magnetism and heat effect due to their superficial effect, bulk effect, quantum dimension effect and macrocosmic quantum tube effect, especially nanometer scale rare earth oxide such as neodymium oxide. Here, we report preparation of the nanometer-scale iron oxide and rare earth oxide particles via an easy thermo-decomposition method of their complexes. The complexes are obtained by reaction of their corresponding nitrate with o-nitro-benzoic acid. The characterization of the complexes and oxide particles are presented.(1) Nanometer-scaleα-Fe2O3 particles (10~45 nm) have been synthesized by the thermo-decomposition of a new Fe3+ complexes taking o-nitro-benzoic acid as ligand. Structure and properties of the Fe3+ complexes have been confirmed by XRD, FT-IR and DSC-TGA. And theα-Fe2O3 powders have been characterized by XRD, TEM, VSM and BET. Theα-Fe2O3 powders exhibit a specific surface area of 65.44 m2·g-1. Control over the particle size, surface area, yield, and state of agglomeration could be achieved through variation of the experimental conditions.The nanometer-scale Nd2O3 particles (20~40 nm) have been synthesized by the thermo-decomposition of a new Nd3+ complexes taking o-nitro-benzoic acid as ligand. Structure and properties of the Nd3+ complexes have been confirmed by XRD, FT-IR and TGA. The Nd2O3 powders have been characterized by XRD and TEM.(2) [Nd(o-NO2-C6H4COO)3(DMF)2]2 and [Ln(o-NO2-C6H4COO)3(DMF)2]2 (Ln=Ce, Sm) are synthesized, and the crystal structure of the complexes is characterized by the methods of FT-IR, 1H NMR, UV, elemental analysis, fluorescent emission spectra and X-ray single crystal diffraction.The first complex resides on an inversion center. The results show that the complex crystallizes in a triclinic system, space group P-1 with cell parameters a=1.18652(12) nm, b=1.24784(13) nm, c=1.29958(13) nm,α=64.220(1)°,β=66.306(1)°,γ=71.825(1)°, V=1.5645(3) nm3, Dc=2.167 mg·m-1, Z=2,μ=3.415 mm-1, F(000)= 986. Each Nd (Ⅲ) atom is bridged by four o-nitrobenzoates and chelated by one o-nitrobenzoate. The Nd (Ⅲ) atom is eight-coordinated by six oxygen atoms from five o-nitrobenzoates and two oxygen atoms from two DMF molecules. Hydrogen bonds and aromaticπ…πstacking interactions assemble the title complex into a three dimensional network. Luminescence measurement shows that the complex emits fluorescence.The second complex also resides on an inversion center. The results show that the complex crystallizes in a triclinic system, space group P-1 with cell parameters a=1.18284(6) nm, b=1.25082(7) nm, c=1.30203(7) nm,α=63.965(10)°,β=66.390(10)°,γ=71.738(10)°, V=1.5637 (14) nm3, Dc=1.688 mg·m-1, Z=2,μ=1.954 mm-1, F(000)=794. Each Ln (Ⅲ) atom is bridged by four o-nitrobenzoates and chelated by one o-nitrobenzoate. The Ln (Ⅲ) atom is eight-coordinated by six oxygen atoms from five o-nitrobenzoates and two oxygen atoms from two DMF molecules. Hydrogen bonds and aromaticπ…πstacking interactions assemble the title complex into a three dimensional network. Luminescence measurement shows that the complex emits fluorescence.
【Key words】 Nanometer oxide; Thermo-decomposition; Synthesis; Characterization; Crystal structure; Fluorescence;
- 【网络出版投稿人】 陕西师范大学 【网络出版年期】2008年 02期
- 【分类号】O641.4
- 【下载频次】197