钝感炸药DNP和NTO的酸性解离常数的测定方法研究

采用滴定法、半中和法、p H法、电导率法、紫外分光光度法5种方法,测定了3,4-二硝基吡唑(DNP)和3-硝基-1,2,4-三唑-5-酮(NTO)两种钝感炸药的酸性解离常数p Ka,并对不同方法所测的结果进行比较和讨论。结果表明,滴定法、半中和法、紫外分光光度法3种方法适合DNP类物质的p Ka测定,实验结果基本一致,与文献值的相对误差RE5%;滴定法、p H法更适合NTO类物质的p Ka测定,实验结果基本一致,与文献值的相对误差RE4%。DNP的p Ka大于NTO的p Ka,即DNP比NTO的酸性弱,对设备等的腐蚀作用较小,更适宜用作熔铸炸药载体。根据这5种酸性解离常数测定方法的优缺点,讨论了测定不同性质物质的p Ka时可选用的方法。     

吡唑及吡嗪类含能化合物研究进展

吡唑和吡嗪分别为分子中含两个氮原子的五元和六元杂环,是富氮杂环化合物的理想结构单元.部分具有生成焓高、热稳定性好和感度较低等特点.介绍了吡唑、吡嗪类高氮杂环含能化合物的合成、性能以及在含能材料中的应用研究进展,其中LLM-105和ANPZ-i在钝感炸药中应用前景良好,预测了两类含能化合物的发展前景.     

3,4-二硝基吡唑热分解及非等温动力学

采用TG-DSC综合热分析的方法,对3,4-二硝基吡唑(DNP)的热分解和非等温动力学进行了研究。结果表明DNP的热分解分两阶段进行,并且在升温速率达到15K/min时才能明显区分。分别采用Archar微分法和Coats-Redfen积分法计算了DNP第一阶段热分解反应动力学参数:Ea=91.6kJ.mol-1,lnA=42.7s-1。最可能的DNP热分解机理为随机成核和随后生长机理,符合动力学机理函数Avrami-Erofeev方程,n=3。     

壬基酚聚氧乙烯醚二聚和三聚表面活性剂的合成及表面性质

合成了系列壬基酚聚氧乙烯醚二聚表面活性剂(DNP)和三聚表面活性剂(TNP), 用核磁共振、红外光谱和元素分析等手段对其结构进行了表征, 并用表面张力法和稳态荧光法对DNP和TNP的表面性能进行了研究. 结果表明, 随着氧乙烯(EO)单元数的增长, DNP和TNP的临界胶束浓度(cmc)值逐渐增大; DNP和TNP的cmc值较相应的单体壬基酚聚氧乙烯醚表面活性剂(NP)明显降低, 显示了较高的表面活性、吸附能力和润湿能力.     

共晶含能材料研究进展

共晶是不同种类的分子(两种或两种以上)通过氢键等分子间相互作用,形成具有特定结构和性能的多组分分子晶体,不同含能材料形成共晶可以有效改善炸药的感度、安全性等性能。针对目前高能炸药的改性需求,共晶在含能材料领域中的应用具有巨大的潜力。综述了共晶的形成原理及生长特性,总结了常见共晶的制备方法和表征方法,评述了含能材料共晶的研究现状和发展前景。     

反相高效液相色谱法测定ε-六硝基六氮杂异伍兹烷纯度

六硝基六氮杂异伍兹烷(HNIW)是1998年才合成的一种多环笼型硝胺高能炸药,它的学名是2,4,6,8,1O-六硝基-2,4,6,8,1O,12-六氮杂四环[5.5.O.O~(5.9).O~(3.11)]十二烷,ε-HNIW的密度、爆速及爆压超过现在含能材料领域内独鳌头的王牌炸药奥克托今(HMX)5%～8%,而由圆筒实验及钽板加速实验测得的能量输出则可超过HMX14%.目前,美国已在进行HNIW的中试生产,中国及其他国家正在积极研究HNIW的生产和应用.因此,建立HNIW纯度的分析方法,对于HNIW生产工艺改进、产品质量控制及合HNIW混合炸药和推进剂的成分分析都是迫切需要的.美国的S.A.Oehrle曾采用胶束电动色谱(MECC)及高效液相色谱(HPLC)测定了混合炸药中包括HNIW在内的十多种组分的保留时间;瑞典的B.Persson等也以HPLC测出了混合炸药中三硝基氮杂环丁烷(TNAZ)和HNIW的含量;日本的儿玉保也曾提及他们合成的HNIW经HPLC测定其纯度为99%.但上述报道均不够详细,而且多限于分析含HNIW的混合炸药.作者制得了高纯度的ε-HNIW样品,并以HPLC对所得的HNIW样品进行了纯度测定,得到峰面积归一化定量法分析结果,并对结果进行了讨论.     

新型丁二炔-二酰胺大环化合物的合成及与TTF和DNP在溶液中的络合行为

由三甘醇和四甘醇出发,经炔丙基烷基化、Mitsunobu反应和Eglinton偶联反应3步合成了2个含均苯四甲酸二酰亚胺结构单元以及丁二炔结构单元的大环化合物,关环产率分别为81%和85%.大环化合物及中间体的化学结构经核磁共振氢谱、碳谱、低分辨质谱、高分辨质谱或元素分析等确认.通过氘代丙酮中1HNMR实验以及氯仿中紫外滴定实验研究了这类大环化合物与客体分子四硫富瓦烯(TTF)和1,5-二甲氧基萘(DNP)在溶液中的相互作用,结果发现,大环化合物的核磁化学位移及紫外光谱均发生变化.通过得到的主-客体间的络合常数可知,此类新型大环化合物与TTF和DNP之间有一定的络合作用.     

立体异构单萜醇油酸酯的制备及促透活性评价

本文以互为立体异构体的香叶醇(GER)、橙花醇(NER)为先导化合物,采用酰氯酯化法合成油酸香叶醇酯(GER-dC18)、油酸橙花醇酯(NER-dC18),并考察GER、NER、GER-dC18、NER-dC18作为促透剂对多奈哌齐(DNP)的促透活性差异。通过体外释放试验、红外光谱法和分子模拟技术初步探究其促透机制,结果发现,所选用促透剂不仅能够促进DNP从压敏胶中释放,而且能够作用于角质层脂质及角蛋白并促进水合作用来降低角质层的屏障功能,从而增加DNP的经皮透过。其中,(E)构型的GER-dC18对DNP具有最优的促透效果,有望为经皮制剂的开发提供关键的辅料。     

吡唑酸类化合物的合成研究

通过探究吡唑酸的四种不同合成方法,筛选了适合于工业化生产的合成路线;并利用农药氯虫酰胺重要中间体--3-溴-1-(3-氯吡啶-2-基)-1H-吡唑-5-甲酸的合成进行了验证,产物结构经核磁共振谱(1H NMR)确认.     

甲烷单加氧酶的模型化合物:以树脂为载体的双铁(Ⅲ)催化剂的合成、表征及催化性能的研究

使用树脂为载体,合成了6种新的双铁(Ⅲ)催化剂,成功的模拟了可溶性甲烷单加氧酶(MMO)的双核铁中心.这是首次使用树脂作为载体合成模拟MMO的非均相催化剂.在室温下以乙腈为溶剂,30%的过氧化氢或特丁基过氧化氢做氧化剂,环己烷或乙苯作为底物的反应中,催化剂具有MMO相似的催化活性.其中,使用大孔氨甲基树脂为载体合成的催化剂能有效地催化乙苯氧化得到较好的转化率(总收率达69.9%,TON值达55.3).同时研究了树脂的颗粒大小及阴离子供体对催化性能的影响.使用粒径0.675～0.280 mm的树脂和ClO-4的阴离子供体所合成的催化剂具有很好的催化活性.最后探讨了催化剂的回收和再利用.     

Overview of Synthetic Methods to Prepare Plasmonic Transition-Metal Nitride Nanoparticles

The search for new plasmonic materials that are low-cost, chemically and thermally stable, and exhibit low optical losses has garnered significant attention among researchers. Recently, metal nitrides have emerged as promising alternatives to conventional, noble-metal-based plasmonic materials, such as silver and gold. Many of the initial studies on metal nitrides have focused on computational prediction of the plasmonic properties of these materials. In recent years, several synthetic methods have been developed to enable empirical analysis. This review highlights synthetic techniques for the preparation of plasmonic metal nitride nanoparticles, which are predominantly free-standing, by using solid-state and solid–gas phase reactions, nonthermal and arc plasma methods, and laser ablation. The physical properties of the nanoparticles, such as shape, size, crystallinity, and optical response, obtained with such synthetic methods are also summarized.     

Efficient templated synthesis of donor-acceptor rotaxanes using click chemistry

The mild reaction conditions, remarkable functional group compatibility, and complete regioselectivity of the Cu-catalyzed Huisgen 1,3-dipolar cycloaddition ("click chemistry") between organic azides and terminal alkynes have led to a threading-followed-by-stoppering approach to the synthesis of donor-acceptor rotaxanes incorporating cyclobis(paraquat-p-phenylene) (CBPQT4+) as the pi-accepting ring component. Rotaxane formation is initiated by reacting azide-functionalized pseudorotaxanes containing pi-donating 1,5-dioxynaphthalene (DNP) recognition units with appropriate alkyne-functionalized stoppers. The high yields obtained in this efficient, kinetically controlled post-assembly covalent modification, as well as the excellent convergence of the synthetic protocol, are demonstrated by the preparation of [2]-, [3]-, and [4]rotaxanes containing multiple DNP/CBPQT4+ donor-acceptor recognition motifs.     

磷烯的制备、结构、性质及器件应用

磷烯是继石墨烯之后一种新型的二维材料,具有优异的物理、化学和机械性能,在各类器件中具有大的应用潜力。目前对磷烯的最新制备方法、特性调控和应用的系统总结较少。本文对磷烯的制备、结构、性质、改性方法及其器件应用进行了系统的综述。首先概括了磷烯"自上而下"和"自下而上"的制备方法,对其结构和性质进行了总结,同时讨论了磷烯的修饰改性方法,最后对磷烯的器件应用进行了较详细的介绍,并在此基础上对磷烯的研究方向和前景进行了展望。     

Redox-controllable amphiphilic [2]rotaxanes

With the fabrication of molecular electronic devices (MEDs) and the construction of nanoelectromechanical systems (NEMSs) as incentives, two constitutionally isomeric, redox-controllable [2]rotaxanes have been synthesized and characterized in solution. Therein, they both behave as near-perfect molecular switches, that is, to all intents and purposes, these two rotaxanes can be switched precisely by applying appropriate redox stimuli between two distinct chemomechanical states. Their dumbbell-shaped components are composed of polyether chains interrupted along their lengths by i) two pi-electron rich recognition sites-a tetrathiafulvalene (TTF) unit and a 1,5-dioxynaphthalene (DNP) moiety-with ii) a rigid terphenylene spacer placed between the two recognition sites, and then terminated by iii) a hydrophobic tetraarylmethane stopper at one end and a hydrophilic dendritic stopper at the other end of the dumbbells, thus conferring amphiphilicity upon these molecules. A template-directed protocol produces a means to introduce the tetracationic cyclophane, cyclobis(paraquat-p-phenylene) (CBPQT(4+)), which contains two pi-electron accepting bipyridinium units, mechanically interlocked around the dumbbell-shaped components. Both the TTF unit and the DNP moiety are potential stations for CBPQT(4+), since they can establish charge-transfer and hydrogen bonding interactions with the bipyridinium units of the cyclophane, thereby introducing bistability into the [2]rotaxanes. In both constitutional isomers, (1)H NMR and absorption spectroscopies, together with electrochemical investigations, reveal that the CBPQT(4+) ring is predominantly located on the TTF unit, leading to the existence of a single translational isomer (co-conformation) in both cases. In addition, a model [2]rotaxane, incorporating hydrophobic tetraarylmethane stoppers at both ends of its dumbbell-shaped component, has also been synthesized as a point of reference. Molecular synthetic approaches were used to construct convergently the dumbbell-shaped compounds by assembling progressively smaller building blocks in the shape of the rigid spacer, the TTF unit and the DNP moiety, and the hydrophobic and hydrophilic stoppers. The two amphiphilic bistable [2]rotaxanes are constitutional isomers in the sense that, in one constitution, the TTF unit is adjacent to the hydrophobic stopper, whereas in the other, it is next to the hydrophilic stopper. All three bistable [2]rotaxanes have been isolated as green solids. Electrospray and fast atom bombardment mass spectra support the gross structural assignments given to all three of these mechanically interlocked compounds. Their photophysical and electrochemical properties have been investigated in acetonitrile. The results obtained from these investigations confirm that, in all three [2]rotaxanes, i) the CBPQT(4+) cyclophane encircles the TTF unit, ii) the CBPQT(4+) cyclophane shuttles between the TTF and DNP stations upon electrochemical or chemical oxidation/reduction of the TTF unit, and iii) folded conformations are present in which the CBPQT(4+) cyclophane, while encircling the TTF unit, interacts through its pi-accepting bipyridinium exteriors with other pi-donating components of the dumbbells, especially those located within the stoppers.     

Remarkably flexible quinazolinones—synthesis and biological applications

Even though several quinazolinone derivatives have been synthesized, still there is a constant demand for designing and synthesis of new quinazolinone derivatives by fine-tuning the electronic and steric properties of substituents due to their interesting structure-based biological utilities and the versatile chemistry. While many of the synthetic routes are useful as building blocks in synthetic organic chemistry, the drawbacks of some of these methods like unsatisfactory or variable yields, prolonged reaction times, inadequate tolerance to other substrates, including the use of costly catalysts/reagents. This review article is mainly focused on various synthetic routes for the preparation of quinazolinones, their important properties and applications.     

A redox-driven multicomponent molecular shuttle

A multicomponent [2]rotaxane designed to operate as a molecular shuttle driven by light energy has been constructed, and its properties have been investigated. The system is composed of (1) a light-fueled power station, capable of using the photon energy to create a charge-separated state, and (2) a mechanical switch, capable of utilizing such a photochemically generated driving force to bring about controllable molecular shuttling motions. The light-fueled power station is, in turn, a dyad comprising (i) a pi-electron-accepting fullerene (C60) component and (ii) a light-harvesting porphyrin (P) unit which acts as an electron donor in the excited state. The mechanical switch is a redox-active bistable [2]rotaxane moiety that consists of (i) a tetrathiafulvalene (TTF) unit as an efficient pi-electron-donor station, (ii) a dioxynaphthalene (DNP) unit as a second pi-electron-rich station, and (iii) a tetracationic cyclobis(paraquat-p-phenylene) (CBPQT4+) pi-electron-acceptor cyclophane, which encapsulates the better pi-electron-donating TTF station. Diethylene glycol spacers were conveniently introduced between the electroactive components in the dumbbell-shaped thread to facilitate the template-directed synthesis of the [2]rotaxane. A modular synthetic approach was undertaken for the overall synthesis of this multicomponent bistable [2]rotaxane, beginning with the syntheses of the P-C60 dyad unit and the two-station TTF-DNP-based [2]rotaxane separately, using conventional synthetic methodologies. These two components were finally stitched together by an esterification to afford the target rotaxane. Its structure was characterized by 1H NMR spectroscopy and mass spectrometry as well as by UV-vis-NIR absorption spectroscopy and voltammetry. The observations reflect remarkable electronic interactions between the various units, pointing to the existence of folded conformations in solution. The redox-driven shuttling process of the CBPQT4+ ring between the two competitive electron-rich recognition units, namely, TTF and DNP, was investigated by electrochemistry and spectroelectrochemistry as a means to verify its operational behavior prior to the photophysical studies related to light-driven operation. The oxidation process of the TTF unit is dramatically hampered in the rotaxane, thereby reducing the efficiency of the shuttling motion. These results confirm that, as the structural complexity increases, the overall function of the system no longer depends simply on its "primary" structure but also on higher-level effects which are reminiscent of the secondary and tertiary structures of biomolecules.     

The Dawn of Functional Organoarsenic Chemistry

Organoarsenic chemistry was actively studied until the middle of 20th century. Although various properties of organoarsenic compounds have been computationally predicted, for example, frontier orbital levels, aromaticity, and inversion energies, serious concern to the danger of their synthetic processes has restricted experimental studies. Conventional synthetic routes require volatile and toxic arsenic precursors. Recently, nonvolatile intermediate transformation (NIT) methods have been developed to safely access functional organoarsenic compounds. Important intermediates in the NIT methods are cyclooligoarsines, which are prepared from nonvolatile inorganic precursors. In particular, the new approach has realized experimental studies on conjugated arsenic compounds: arsole derivatives. The elucidation of their intrinsic properties has triggered studies on functional organoarsenic chemistry. As a result, various kinds of arsenic-containing π-conjugated molecules and polymers have been reported for the last few years. In this minireview, progress of this recently invigorated field is overviewed.     

New Synthetic Method of trans, trans-Styrylstilbene

Styrylstilbenes and their derivatives are a kind of organic luminescent materials. A variety of synthetic methods have been reported, and their physical properties have been studied. [1,2] A series of para-substituted styrylstilbenes were synthesized by Wittig or Arbusor-Horner reaction as a key step forming C=C bonds.     

联三吡啶配体及其衍生物合成进展

金属-配体间的配位作用是超分子化学中最重要的相互作用之一, 寡聚吡啶配体可以与许多过渡金属离子配位, 形成具有独特磁、光物理和电化学性质的过渡金属络合物, 因此联三吡啶配体的合成及其过渡金属络合物性能研究引起化学家的广泛关注. 综述了联三吡啶配体及其衍生物的合成方法, 主要包括成环缩合反应、过渡金属催化的偶联反应以及其它方法, 并选取具有代表性的实例对联三吡啶配体的结构和合成方法进行详细地阐述.     

Synthesis and application of poly(phenylene ethynylene)s for bioconjugation: a conjugated polymer-based fluorogenic probe for proteases

A set of carboxylate-functionalized poly(phenylene ethynylene)s (PPEs) has been synthesized in which the carboxylic acid groups are separated from the polymer backbone by oligo(ethylene glycol) spacer units. These polymers are soluble in water and organic solvents and have photophysical properties that are sensitive to solvent conditions, with high salt content and the absence of surfactant promoting the formation of aggregates of relatively low quantum yield and long fluorescence lifetime. Quenching of these materials by the dinitrophenyl (DNP) chromophore (K(SV) approximately 10(4)) is also highly solvent-dependent. The presence of carboxylate groups far from the polymer backbone appended to each repeating unit allows for the postpolymerization modification of these PPEs with peptides by methods analogous to those described for carboxylate-functionalized small-molecule dyes. Covalent attachment of the fluorescence-quenching 14-mer Lys(DNP)-GPLGMRGLGGGGK to the PPE results in a nonemissive substrate whose fluorescence is restored upon treatment with trypsin. The rate of fluorescence turn-on in this case is increased 3-fold by the presence of surfactant, though the actual rate of peptide hydrolysis remains the same. A small-molecule mimic of the polymer-peptide system shows a smaller fluorescence enhancement upon treatment with trypsin, illustrating the value of polymer-based amplification in this sensory scheme.