几种典型有机叠氮化物的高压研究

发布时间：2018-01-08 06:27

本文关键词：几种典型有机叠氮化物的高压研究　出处：《吉林大学》2017年博士论文　论文类型：学位论文

【摘要】：能源是人类生活的物质基础,也是科学研究的永恒课题,其中高能量密度材料的合成一直是凝聚态物理与材料科学研究中的热点问题。压力是独立于温度和组分的基本热力学参数,可以改变原子排列和电子态分布,从而引起物质的结构发生变化,使得常压下难以合成的材料在压力的作用下得以实现。单键态的聚合氮以其较高的能量密度(高达38.4 k J/cm3)和清洁的产物(氮气)成为物理学中十分重要的研究领域。高压是合成聚合氮的一种有效方法。自从叠氮化钠在3300K和120 GPa的条件下成功转变为常压下亚稳态的单键态聚合氮之后,叠氮化物成为高压下合成聚合氮的理想前驱体。但是大量无机叠氮化物的理论和实验研究表明,叠氮根在高压下不容易弯曲,从而很难发生电子轨道杂化,进而发生氮聚合的压力较高,这限制了实际应用与科学研究。有机叠氮化物作为叠氮化物的另一个重要分支,其叠氮基的电子结构与无机叠氮化物中叠氮根的电子结构不同。这种不同的电子结构会使叠氮基表现出异于叠氮根的高压行为,很可能会更容易形成聚合氮,从而降低发生氮聚合的压力点。本论文采用金刚石对顶砧装置,利用高压拉曼散射、高压红外吸收以及高压同步辐射X光衍射技术,对三类典型的有机叠氮化物进行系统的高压研究,探究其高压结构相变和相变类型,揭示了叠氮基的高压行为规律以及影响叠氮基高压行为的因素。首先,我们对卞基叠氮化物叠氮苄进行高压拉曼散射和高压同步辐射X光衍射实验,实验的最高压力为30.8 GPa。通过实验与理论计算相结合,对叠氮苄的常压拉曼光谱进行完整的指认。在0.67 GPa和2.7 GPa时,叠氮苄分别发生一次构象改变和一次结构相变。构象改变主要是由叠氮苄中的亚甲基旋转引起的。2.7 GPa时,拉曼峰呈现反常红移现象,并且在XRD谱中出现一些衍射点,同时原本属于液态的衍射环消失,表明叠氮苄转变成固态,发生液固相变。高压下,叠氮基受到亚甲基的影响而发生旋转,并在25.6 GPa时叠氮基分解。我们发现叠氮基的分解压力点比叠氮根的分解压力点要低,这可能有利于叠氮基在更低压力下形成聚合氮。当达到实验的最高压力30.8 GPa时,叠氮苄转化为非晶态。其次,我们对磺酰叠氮化物4-乙酰氨基苯磺酰叠氮(4-ABSA)、4-羧基苯磺酰叠氮(4-CBSA)、4-对甲苯磺酰叠氮(4-Ts N3)分别进行高压拉曼散射、高压红外吸收和高压同步辐射X光衍射实验。4-ABSA在0.8~2 GPa和4.2 GPa发生两次结构相变,在13GPa时转变为非晶态。第一次相变是由于苯环变形和甲基旋转造成的。第二次相变是由于甲基的扭曲和分子间氢键键能的改变。叠氮基在高压下旋转。4-CBSA在0.5 GPa和2.5~5.5 GPa的压力范围内发生两次结构相变,在14.6 GPa时转变为非晶态。由于分子构象的改变使4-CBSA从相I变到相II,由于苯环的变形和分子间氢键的改变使4-CBSA从相II变到相III。叠氮基在压力的作用下先弯折后旋转,到10.5 GPa时开始分解。4-Ts N3在0.7 GPa、2.7 GPa、6.3 GPa发生三次结构相变,在15.6 GPa时转变为非晶态。第一次相变是由于C-H…?相互作用重排使晶体结构的对称性降低。第二次相变是由于4-Ts N3分子构象发生改变。第三次相变是由磺酰基发生旋转造成的,并且受到磺酰基的影响,叠氮基发生弯折。最后,我们对叠氮三甲基锡烷(TMSn A)进行高压拉曼散射、高压红外吸收和高压同步辐射X光衍射实验,实验的最高压力为35.2 GPa。常压下,TMSn A中的叠氮基是直线型非对称的,有着部分离子性和部分共价性的特点。在1.4 GPa时,甲基的旋转使分子内有机基团的相对位置发生微小的改变,引起TMSn A的第一次结构相变。在6.6 GPa时,由于甲基的变形造成晶格的扭曲使TMSn A发生第二次结构相变,进而造成叠氮基的对称性降低,共价性增强而离子性减弱。叠氮基的这种特殊性质可能使相邻的叠氮基在足够高的压力下发生键合,从而发生氮聚合反应。
[Abstract]:Energy is the material basis of human life, is the eternal subject of scientific research, the synthesis of high energy density materials has been a hot issue in the study of condensed state physics and material science. The pressure is the basic thermodynamic parameters independent of temperature and composition, can change the atomic arrangement and distribution of electronic states, causing the material structure. It is difficult to change, so under normal pressure synthetic materials under the action of pressure can be achieved. The single state of polymerization nitrogen for its high energy density (up to 38.4 K J/cm3) and clean product (nitrogen) become an important research field in physics. High pressure is an effective method for synthesis of polymeric nitrogen since. After the successful change of sodium azide in the 3300K and 120 GPa under the condition of single metastable state polymerization under atmospheric pressure nitrogen, azide become ideal polymer precursor synthesis under high pressure nitrogen. But the large Theoretical and Experimental Research on the amount of inorganic azides azide showed that under high pressure is not easy to bend, thus it is very difficult to track electronic hybrid, and high pressure nitrogen polymerization, which limits the practical application and scientific research. The organic azide as another important branch of azide, electronic structure and electronic structure the inorganic azido azides azide in different. This will make the different electronic structures of azido show high pressure behavior different from azide, it may be easier to form polymeric nitrogen, so as to reduce the occurrence of pressure nitrogen polymerization. This paper adopted a diamond anvil cell, using the High Pressure Raman scattering technology, X ray diffraction with synchrotron radiation infrared absorption and high pressure, high pressure on the system of three kinds of typical organic azides, explore the high-pressure structure transition and transformation type, reveals the stack The factors of nitrogen based high pressure behavior and affect the azido pressure behavior. First, we performed high-pressure Raman scattering and high pressure on the benzyl azide benzylazide synchrotron radiation X ray diffraction experiment, the highest pressure test is 30.8 GPa. by the combination of experiment and theoretical calculation, complete identify the Raman spectrum of atmospheric stack n benzyl. At 0.67 GPa and 2.7 GPa, respectively, benzylazide a conformational change and a structural phase transition. The conformational change is mainly caused by benzylazide caused by the rotating.2.7 GPa methylene, the Raman peaks exhibit anomalous redshift, and some diffraction point appeared in the XRD spectrum, diffraction ring at the same time belong to the original liquid disappears, indicates the transformation of benzylazide into solid liquid solid phase transition. Under high pressure, azido methylene caused by rotation, and in 25.6 GPa azido decomposition. We found the azido branch The pressure point is lower than the decomposition pressure of azide, it may be beneficial to the formation of azido nitrogen polymer at lower pressure. When the pressure reaches the highest at 30.8 GPa, benzylazide into amorphous. Secondly, we of sulfonyl azide 4- p-acetamido benzene sulfonyl azide (4-ABSA 4-), carboxyl benzene sulfonyl azide (4-CBSA), 4- toluene-4-sulfonyl azide (4-Ts N3) were high pressure Raman scattering, two phase transition occurs at 0.8~2 GPa and 4.2 GPa high pressure infrared absorption and high pressure synchrotron radiation X ray diffraction experiment.4-ABSA, when 13GPa was transformed into amorphous first. Phase change is due to deformation caused by the rotation of the benzene and methyl. The second phase is due to distortions and molecular methyl hydrogen bonding energy. The change of azide under high pressure rotating.4-CBSA in the pressure range of 0.5 GPa and 2.5~5.5 GPa in the two structural phase transition at 14.6 GPa, non Due to the molecular conformational change of crystalline. The 4-CBSA from I to II phase, due to deformation and molecular hydrogen bonds between the benzene ring changed from 4-CBSA to III. phase II phase azide under the pressure of the first bending rotation to 10.5 GPa when.4-Ts N3 began to decompose at 0.7 GPa, 2.7 GPa 6.3, GPa three phase transition at 15.6 GPa into amorphous state. The first phase is due to C-H... ? interaction reduces the rearrangement of the symmetry of crystal structure. The second phase is due to the 4-Ts N3 molecular conformation changed. The third phase is composed of sulfonyl occurrence caused by rotation, and is influenced by sulfonyl azide, bend. Finally, we three methyl tin alkyl azide (TMSn A) High Pressure Raman scattering, infrared absorption and high pressure synchrotron radiation X ray diffraction experiment, the highest pressure experiment was 35.2 GPa. under normal pressure, TMSn A azide is linear asymmetric, with characteristics of ionic and covalent properties. In 1.4 GPa, the relative position of methyl rotation. Intramolecular organic groups changed slightly, causing the first structural phase transition of TMSn A. At 6.6 GPa, due to the lattice distortion caused by the deformation of methyl TMSn A second structural phase transition, which caused the symmetry of azido decreasing covalency The special properties of the azido group may make the adjacent azido groups bonding at high enough pressure, so that the nitrogen polymerization will occur.

【学位授予单位】：吉林大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：O521

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