三维无溶剂含能Ag-MOF的制备、热分解动力学及爆炸性能

Solvent molecules can significantly reduce the heat of detonation and stability of energetic metal-organic framework (EMOF) materials, and the development of solvent-free EMOFs has become an effective strategy to prepare high-energy density materials. In this study, a solvent-free EMOF, [Ag₂(DTPZ)]_n (1) (N% = 32.58%), was synthesized by reacting a high-energy ligand, 2, 3-di(1H-tetrazol-5-yl)pyrazine (H₂DTPZ), with silver ions under hydrothermal conditions, and it was structurally characterized by elemental analysis, infrared spectroscopy, X-ray diffraction, and thermal analysis. In 1, the DTPZ²⁻ ligands that adopted a highly torsional configuration bridged the Ag⁺ ions in an octadentate coordination mode to form a three-dimensional framework (ρ = 2.812 g∙cm⁻³). The large steric effect and strong coordination ability of DTPZ²⁻ effectively prevented the solvent molecules from binding with the metal centers or occupying the voids of 1. Moreover, the strong π-π stacking interactions [centroid-centroid distance = 0.34461(1) nm] between the tetrazole rings in different DTPZ²⁻ ligands provided a high thermal stability to the framework (T_e = 619.1 K, T_p = 658.7 K). Thermal analysis showed that a one-step rapid weight loss with intense heat release primarily occurred during the decomposition of 1, suggesting potential energetic characteristics. Non-isothermal thermokinetic analyses (based on the Kissinger and Ozawa-Doyle methods) were performed using differential scanning calorimetry to obtain the thermoanalysis kinetic parameters of the thermodecomposition of 1 (E_a = 272.1 kJ·mol⁻¹, E_o = 268.9 kJ·mol⁻¹; lgA =19.67 s⁻¹). The related thermodynamic parameters [enthalpy of activation (ΔH^≠ = 266.9 kJ·mol⁻¹), entropy of activation (ΔS^≠ = 125.4 J·mol⁻¹·K⁻¹), free energy of activation (ΔG^≠ = 188.3 kJ·mol⁻¹)], critical temperature of thermal explosion (T_b = 607.1 K), and self-accelerating decomposition temperature (T_SADT = 595.8 K) of the decomposition reaction were also calculated based on the decomposition peak temperature and extrapolated onset temperature when the heating rate approached zero. The results revealed that 1 featured good thermal safety, and its decomposition was a non-spontaneous entropy-driven process. The standard molar enthalpy for the formation of 1 was calculated to be (2165.99 ± 0.81) kJ·mol⁻¹ based on its constant volume combustion energy determined using a precise rotating oxygen bomb calorimeter. Detonation and safety performance tests revealed that 1 was insensitive to impact and friction, and its heat of detonation (10.15 kJ·g⁻¹) was higher than that of common ammonium nitrate explosives, such as octogen (HMX), hexogene (RDX), and 2, 4, 6-trinitrotoluene (TNT), indicating that 1 is a promising high-energy and insensitive material.     

光纤光谱仪的多样化组装及应用——介绍一个仪器分析实验

介绍了一个本科生的仪器分析实验——光纤光谱仪的多样化组装及应用。利用光源、光纤和电荷耦合器件检测器等部件,组装出紫外-可见光谱仪、分子荧光光谱仪、近红外光谱仪、拉曼光谱仪和激光诱导荧光光谱仪。通过本实验,不仅能够拓展传统光学实验的内容,而且可以通过自己动手组装仪器,培养学生的专业实践能力和知识应用能力。     

Co_2Si@C催化剂的合成及其加氢脱硫性能

采用微波法制备了Co_2Si@C催化剂并对其在加氢脱硫反应中的催化性能进行了研究.通过XRD、 XPS、 TEM和N_2-物理吸附表征分析Co_2Si@C催化剂的组成和结构. Co_2Si@C催化剂具有一致的介孔结构,高钴含量(21%)、高比表面积(116.6 m~2·g~(-1))和均匀分布的纳米粒子.由于硅原子对钴原子结构和参数的修饰、纳米粒子效应和高金属含量等因素, Co_2Si@C催化剂在温和的反应条件下(340℃和3.0 MPa)具有良好的加氢脱硫活性和对直接脱硫(DDS)反应途径的高选择性,产物联苯的选择性超过了60%.     

两种表征核酸适配体-靶蛋白亲和作用的毛细管电泳方法比较

适配体-靶分子间的亲和作用表征是理解和应用核酸适配体发挥特异亲和作用的基本前提,CE技术则为上述表征提供了多模式的简捷途径,但多种模式体系间的结果往往存在差异,导致CE亲和评价可靠性和进一步应用受到限制,亟须建立多CE方法测定适配体-靶分子间亲和作用的系统比较研究。该研究以凝血酶及其特异性作用于肝素结合位点的适配体29mer为模型体系,基于CE-激光诱导荧光检测,引入CE-迎头分析（FA）评价方法,并比较其与预平衡-毛细管区带电泳（PE-CZE）的异同。首先进行了CE-FA方法分离条件的优化,37 ℃、0.5 h孵育完全后进样,进样时间为30 s,在较低工作温度（15 ℃）、较短毛细管长度（30 cm）及生物相容性好的缓冲体系2×TG（Tris-甘氨酸缓冲液,pH 8.5）条件下,经15 kV分离时,得到了稳定的荧光标记29mer（F29mer）-凝血酶复合物及游离F29mer平台峰。加入1 g/L牛血清白蛋白（BSA）,有效提高了CE-FA平台峰高及迁移时间的重复性。详细讨论了两种方法下6种拟合方式的结果及特点。针对CE-FA和PE-CZE法,以结合适配体/游离适配体的浓度比对游离适配体浓度非线性拟合、平台峰高变化对浓度间的非线性拟合、平衡混合物的非平衡CE（NECEEM）计算等进行拟合。结果表明,6种拟合结果中5种不存在显著性差异,得到的解离常数（K_d）值均介于24~64 nmol/L范围。CE-FA法中的3种拟合结果符合度较好,说明CE-FA法易于在非平衡的CE分离体系下保持适配体-复合物间的结合-解离平衡,所测得K_d准确度较高。PE-CZE法中,借由降低的游离F29mer峰高对凝血酶浓度间的非线性拟合所得K_d值偏差过大;选择凝血酶浓度为F29mer浓度的0.5~2倍,且观察到明显的两峰间"指数桥"为前提,可经NECEEM法进行数据计算求解得到较为准确的K_d值。CE-FA法可与PE-CZE法互为印证,提高了亲和作用评价的可靠性。首选推荐使用多浓度平台峰高变化进行非线性拟合的CE-FA法,可相对有效克服高压电场对复合物稳定性的影响,具有适用范围广、方法稳定、结果拟合简便准确等特点。     

基于“1+2”模式的结构化学课程在线教学实践

Since the outbreak of novel coronavirus pneumonia (NCP) at the beginning of this year, Chinese government acted immediately and made some regulations to control the epidemic NCP and promote the recovery of society and industry including education. Chinese universities stayed on the online courses without suspension on teaching and learning. Herein, we report online teaching of structural chemistry course based on the teaching mode of online live broadcast platform, online course resources and management platforms ("1 + 2" mode). This may promote online teaching, and take advantage of online live broadcast and massive open online courses, which achieves good teaching and learning experiences on structural chemistry course.     

Short-focus nematic liquid crystal microlens array with a dielectric layer

ABSTRACT

A short-focus microlens array using dielectric layer and inhomogeneous electric field over a homogeneous nematic liquid crystal (LC) layer is proposed. The top substrate has a planar indium tin oxide (ITO) electrode which is coated on the inner surface. The bottom substrate has strip ITO electrodes which are embedded in the dielectric layers. The inhomogeneous electric field generates a required gradient refractive index profile within the LC layer which, in turn, causes the focusing effect. Due to the thinner LC layer (15 μm), the spherical aberration should be negligible. Moreover, the fabrication process of the proposed microlens array can be easily carried out because of the layer-by-layer configuration. The simulation results show that the focal length of the LC microlens can be continuously tuned from infinity to 0.988 mm with the change of applied voltage.     

通过FGF401的构效关系研究发现一种新颖的FGFR4选择性抑制剂

设计并合成了一系列FGF401类似物以研究其FGFR4抑制、抗肿瘤活性及其构效关系.研究发现了N-(5-氰基-4-(2-甲氧基乙基氨基)吡啶-2-基)-7-甲酰基-6-(N-甲基四氢吡喃-4-甲酰胺)甲基-1,2,3,4-四氢-1,8-萘啶-1-甲酰胺(8ac)不仅在酶和细胞学水平上对FGFR4具有强效的的抑制活性,并表现出了出色的选择性.其活性及选择性优于阳性对照FGF401,并且在HCC (hepatocellular carcinoma)动物移植瘤模型中显著抑制肿瘤生长,还引起了肿瘤萎缩.     

Synthesis,crystal structure and optical property of manganese (II) halides based on pyridine ionic liquids with high quantum yield

Transition Metal Chemistry - Two novel tetrahedral Mn (II) halide single-crystals [(C7H10N)2][MnCl4] (1) and [(C7H10N)2][MnBr4] (2), based on pyridine ionic liquids, have been successfully...     

亚乙基桥联多取代茚-芴锆、铪配合物的合成、结构及催化丙烯选择性齐聚研究

合成并表征了一系列新型亚乙基桥联多取代茚-芴锆、铪配合物ansa-C₂H₄-{2-Me-3-Bn-5,6-[1,3-（CH₂）₃]Ind}-（Flu） ZrCl₂（C1）,ansa-C₂H₄-{2-Me-3-Bn-5,6-[1,3-（CH₂）₃]Ind}（2,7-^tBu₂-Flu） ZrCl₂（C2）,ansa-C₂H₄-{2-Me-3-Bn-5,6-[1,3-（CH₂）₃]Ind}（3,6-^tBu₂-Flu） ZrCl₂（C3）,ansa-C₂H₄-{2-Me-3-Bn-5,6-[1,3-（CH₂）₃]Ind}（Flu） HfCl₂（C4）,并对典型配合物进行了X射线单晶衍射分析,确定了其空间结构.研究了该系列配合物在助催化剂作用下催化丙烯齐聚的行为,考察了催化剂结构及反应条件对齐聚反应的影响.配合物C1～C4与改性甲基铝氧烷（MMAO）或三异丁基铝/三苯甲基四（五氟苯基）硼酸盐（TIBA/TrB）组成的催化体系对丙烯齐聚表现出中等到高的催化活性.锆配合物C2和C3在40～100℃条件下普遍具有较高的β-甲基消除（β-Me消除）选择性（最高可达86%）,实现了分子量M_n在400到4500 g·mol^－1范围内的烯丙基封端丙烯齐聚物的高效合成.铪催化剂体系C4/TIBA/TrB的β-Me消除选择性明显高于相应的锆催化剂体系,同时所得齐聚物的分子量更低.     

铜催化的α-氨基丙二腈的脱氰氧代反应：一种合成叔酰胺的新方法

新反应、新试剂的发展是有机合成化学的重要研究内容,基于前期在α-氨基丙二腈合成方法学方面的工作基础,我们发展了一例铜催化的α-氨基丙二腈的脱氰氧代反应.通过将甲酰胺转化为α-氨基丙二腈后,借助其亲核属性来合成α-氨基丙二腈底物,而后将底物重新转化为酰胺,从而实现形式上的氨基甲酰负离子的亲核加成（取代）反应.该工作首次完成了形式上的甲酰胺碳原子的极性反转,实现了将α-氨基丙二腈作为氨基甲酰负离子替代物的反应新模式,为叔酰胺化合物的合成提供了新的思路和方法,且具有反应条件简单,底物适用性广及适合克级规模制备等特点.