异丙基溴化镁催化脱氧反应

格氏试剂通常以碳负离子形式对亲电试剂进行加成。但是有催化量的Cp_2TiCl_2存在时,具有β质子的烷基格氏试剂往往能发生还原反应或氢镁化反应。例如,使环氧键、碳氧双键、硅氧键、硅卤键、碳卤键、碳氮双键、碳氮三键、碳碳双键、碳碳三键等还原或氢镁化的反应已有报道。但是,对硫氧双键、氮氧键、磷氧双键和砷氧双键的     

偶氮桥联二呋咱:合成及其分子结构-熔点的构效关系

偶氮桥联二呋咱是由两个相同的单呋咱环经偶氮桥联反应所构成的。它是一类热化学性能卓越的富氮高能密度材料,因具有高含氮量、低碳氢、良好的氧平衡、高生成焓并具有共轭结构等优点而备受关注,在高能炸药和固体火箭推进剂等领域有着重要的应用前景。本文从合成角度综述了近二十年来一些典型的偶氮桥联二呋咱类化合物(如3,3'-二氨基-4,4'-偶氮呋咱、3,3'-二硝基-4,4'-偶氮呋咱、偶氮桥联二呋咱卤化物和唑基偶氮桥联二呋咱等)的研究进展,系统讨论了不同侧链取代基对偶氮桥联二呋咱熔点性质的影响,其影响因素主要包括:氢键效应、诱导效应、平面性效应、侧链取代基的体积大小以及对称性作用。通过梳理其分子结构-熔点的构效关系,可为选择性设计和合成具有特定热化学性能的新型偶氮桥联呋咱类化合物提供理论参考。     

T-Jump/FTIR技术研究3,4-二硝基呋咱基氧化呋咱快速热裂解

采用温度快速跃迁原位池与快速扫描傅里叶变换红外联用(T-Jump/FTIR)技术在0.1-0.4MPa压强范围内研究了3,4-二硝基呋咱基氧化呋咱(DNTF)的快速热裂解.试验是以1000℃·s-1的升温速率在800和1000℃的温度下进行,用快速扫描傅里叶变换红外光谱实时跟踪分析DNTF裂解的气相产物.结果表明,DNTF快速热裂解的主要产物CO、CO2、NO和NO2的相对摩尔浓度c*与温度和压强有关,通过分析相对摩尔浓度比(c*NO/c*NO2)随温度和压强的变化,揭示了DNTF中碳硝基C—NO2存在均裂生成NO2和异构化生成NO两条竞争分解的可能途径,同时压强可能抑制呋咱环和氧化呋咱环生成NO的可能性.压强升高使c*CO和c*CO2升高,而使c*CO/c*CO2下降,证明DNTF的分解中存在非均相的气相/凝聚相反应和均相的气相产物间反应的二次或三次过程.     

基于磷杂菲基团化合物的构建与性能*

由于磷杂菲基团具有杂环含磷特性、非共平面性、与分子内或分子间基团的相互作用性、分子极性等特点,能够作为改性基团引入到化合物中用于构建具有新结构和新性能的材料。本文综述了磷杂菲基团衍生物的构建方法和含有磷杂菲基团功能材料的性能以及磷杂菲基团对材料性能的影响规律。介绍了利用9,10-二氢-9-氧杂-10-磷杂菲 10-氧化物（DOPO）的P-H键与不饱和基团醌、醛、酮、碳碳双键、碳氮双键、碳氮三键等进行加成反应获得磷杂菲衍生物的方法和原理。重点总结了含磷杂菲基团的环氧树脂、聚酯、涂料和助剂等化合物的阻燃性能以及磷杂菲基团提高材料阻燃性能的原理;介绍了磷杂菲基团易于与分子内和分子间基团相互作用的性质以及对热致液晶高分子材料液晶性质的影响规律,这一性质也导致了一些磷杂菲化合物的聚集诱导发光现象的发生。此外,磷杂菲基团的极性提高了聚酯和聚酰胺等化合物的分子极性,使这类化合物获得了良好的有机溶解性。     

双呋咱并[3,4-b:3',4']氧化呋咱并[3″,4″-d]氮杂环庚三烯及衍生物爆轰性能的量子化学计算

用密度泛函理论的B3LYP方法,在6-31G*的基础上,全优化计算了双呋咱并[3,4-b:3',4']氧化呋咱并[3″,4″-d]氮杂环庚三烯及其衍生物的几何构型,通过PM6方法计算出物质的生成热,并研究了热力学参数和温度的关系曲线。用Monto-Carlo方法,基于0.001e.born-3等电子密度面包围的空间求得分子平均摩尔体积和理论密度,用Kamlet-Jacobs方程基于理论密度和生成热计算各物质的爆热,爆速和爆压。结果表明:不同的取代基对R-17N键的键长影响较大;且取代基含有苯硝基时,生成热明显增大;取代基含有氨基时,爆轰性能较好。当取代基是氨基时,其化合物的爆轰性能在所有研究的化合物中最好。     

3-氨基-4-氧代氰基呋咱捕获与表征

3,4-双(4-氨基呋咱-3-基)氧化呋咱由活性中间体3-氨基-4-氧代氰基呋咱分子间发生二聚获得,但3-氨基-4-氧代氰基呋咱不稳定,无法通过分离、纯化及光谱鉴定证实其存在.采用4种不同的烯烃与3-氨基-4-氧代氰基呋咱发生1,3-偶极环加成反应得到3-(4-氨基呋咱-3-基)-5-氰基-Δ2-异噁唑啉、3-(4-氨基呋咱-3-基)-5-乙酰氧基-Δ2-异噁唑啉、3-(4-氨基呋咱-3-基)-5-正丁基-Δ2-异噁唑啉及3-(4-氨基呋咱-3-基)-环己烷并-Δ2-异噁唑啉4种Δ2-异噁唑啉衍生物;采用苯甲酰氯为捕获剂,与3-氨基-4-氧代氰基呋咱反应获得了3-氨基-4-(N-苯甲酸基氨基羰基)呋咱化合物;通过红外光谱、核磁共振光谱、质谱、元素分析表征了5种新化合物的结构,提供了活性中间体3-氨基-4-氧代氰基呋咱存在的间接证据.     

3-氨基-4-硝基氧化呋咱含能化合物的设计合成研究

在氧化呋咱环上引入氨基或硝基等功能基团,可提高含能化合物的能量密度和爆炸性能。为了获得更高能量密度的新型含能化合物,本文利用密度泛函理论（DFT）和单、双激发的耦合簇（CCSD）方法探索了以3-酰基叠氮基-4硝基氧化呋咱为起始材料,在二氧六环和水混合溶剂中合成3-氨基-4硝基氧化呋咱的反应机理,给出了反应的势能曲线。结果表明,该反应主要分为两个阶段：3-酰基叠氮基-4硝基氧化呋咱脱N₂后进行Curtious重排产生异氰酸酯;异氰酸酯经水解、羟基扭转、CO₂的脱离形成产物。反应的决速步为CO₂的脱离,能垒为44kcal/mol。因此,加热是实现该合成反应的必要条件。水既绿色环保,又参与反应,是该反应的最佳溶剂。这些结果为3-氨基-4-硝基氧化呋咱的实验合成提供了必要的理论依据。     

氨基呋咱氧化为氨基硝基呋咱的合成研究

研究开发了将氨基呋咱转化为氨基硝基呋咱新的高收率氧化方法. 采用甲烷磺酸为介质, 以过氧化氢、碱或碱土金属和胺为基的氧化物(如钨酸钠或过硫酸铵)混合物的新氧化体系[H2O2/CH3SO3H/Na2WO4或(NH4)2S2O8]代替以硫酸为介质的过氧化氢和过硫酸铵混合物氧化体系, 分别对3,4-二氨基呋咱(DAF)、3,3’-二氨基-4,4’-氧化偶氮呋咱(DAAF)和3,3’-二氨基-4,4’-偶氮呋咱(DAAzF)进行氧化, 以高于65%的产率获得了3-氨基-4-硝基呋咱(ANF)和3-氨基-3’-硝 基-4,4’-氧化偶氮呋咱(ANAF), 并以15%的收率合成得到新化合物3-氨基-3’-硝基-4,4’-偶氮呋咱(ANAzF). 研究表明甲烷磺酸/过氧化氢/碱或碱土金属和胺为基的氧化物混合物是制备同时含有氨基和硝基基团的系列呋咱化合物非常有效的氧化体系.     

硫代四配位磷化物与邻氨基酚反应

在三乙胺存在下,多种硫代磷酰二氯与邻氨基酚反应,经磷硫双键断开并以σ键与磷相连的基团被置换下来等过程,最终生成双环五配位磷化物.苯基硫代环膦酸酯与邻氨基酚反应分别生成螺环五配位磷化物.苯氧基或烷氧基硫代环磷酸酯与邻氨基酚反应,除磷硫键断裂以及苯氧基、烷氧基被置换外,还发生邻亚氨基苯氧基与邻苯二氧基进行相互交换反应.这些反应机理依据磷原子的电负性,氢质子的活泼性以及P-X键的稳定性进行了讨论.     

聚N-甲基-N-(2-甲基丙烯酰氧乙基)-对-甲苯胺的荧光光谱及光诱导接枝丙烯腈共聚合

文献[1]报道N-甲基-N-(2-甲基丙烯酰氧乙基)苯胺(MEMA)单体,由于同一分子中含有缺电子碳碳双键和给电子发色基团(芳叔胺氮上孤对电子),因此当链节克分子浓度相等时,单体的荧光强度要比其均聚物的荧光强度低得多,归之为单体“结构自猝灭”所致。这是由于共存在单体分子中的吸电子双键基团和给电子的荧光基团在光照下于分子内或分子间产生激基复合物所致。这种现象称为“结构自猝灭现象”。聚合物无双键存在,因而其荧光强度比单体高得多。     

Molecular design of trinitromethyl-substituted nitrogen-rich heterocycle derivatives with good oxygen balance as high-energy density compounds

Density functional theory method was used to study the heats of formation (HOFs), electronic structure, energetic properties, and pyrolysis mechanism of a series of trinitromethyl-substituted heterocycle (including triazole, tetrazole, furazan, tetrazine, and fused heterocycles) derivatives. It is found that the fused ring, tetrazine, and tetrazole are effective structural units for increasing the HOFs of the derivatives. The substitution of the combination of nitro and trinitromethyl is very useful for improving their HOFs. The calculated energetic properties indicate that the combination of the nitro and trinitromethyl is very helpful for improving their detonation properties and oxygen balances (OB). Most of the title compounds have a good OB over zero. The OB of six compounds are very high and over 22. An analysis of the bond dissociation energies for several relatively weak bonds suggests that the N–O bond in the ring is a trigger bond for BIII-1, CI-3, and CI-4, and the ring–NO₂ and (NO₂)₂C–NO₂ bond cleavage is likely to happen in thermal decomposition for the remaining compounds. Considering the detonation performance and thermal stability, seven compounds could be regarded as potential candidates for high-energy compounds. Four compounds may be used as the novel high-energy oxidizers.     

Synthesis,Characterization and Properties of Ureido‐Furazan Derivatives

The reaction of a variety of amino‐furazans with chlorosulfonyl isocyanate was carried out to synthesize ureido‐furazans. The nitration to nitro‐ureido‐furazan was successful in the case of 3‐nitro‐4‐nitroureido‐furazan and 3,4‐dinitroureido‐furazan. Furthermore, furazan derivatives linked to a second amino‐oxadiazole were synthesized. All compounds were intensively characterized by X‐ray diffraction measurements, NMR spectroscopy, vibrational spectroscopy (IR, Raman), BAM sensitivity tests and differential thermal analysis. The energetic properties were calculated using Explo5 6.03 .     

Synthesis, Characterization and Thermal Properties of Energetic Compounds Derived from 3-Amino-4-(tetrazol-5-yl)furazan

Five energetic compounds, 3,3‐bis(tetrazol‐5‐yl)‐4,4‐azofurazan (DTZAF), 3‐nitro‐4‐(tetrazol‐5‐yl)furazan (NTZF), hydrazinium 3‐amino‐4‐(tetrazol‐5‐yl)furazan (HATZF), triaminoguanidinium 3‐amino‐4‐(tetrazol‐ 5‐yl)furazan (TAGATZF) and guanylureaium 3‐amino‐4‐(tetrazol‐5‐yl)furazan (MATZF), were prepared using 3‐amino‐4‐(tetrazol‐5‐yl)furazan (ATZF) as starting material and their structures were characterized by FT‐IR, ¹H NMR, ¹³C NMR and elemental analysis. The properties of NTZF were estimated:density is 1.67 g/cm³, enthalpy of formation +415.41 kJ/mol and detonation velocity 8257.83 m/s. The main thermal properties of four compounds, DTZAF, HATZF, TAGATZF and MATZF, were analyzed by TG and DSC techniques and the results showed that their melting points are 251.9, 159.7, 205.4 and 211.4°C, respectively, and their first decomposition temperatures are 256.7, 258.6, 231.7 and 268.6°C, respectively. The fact that their decomposition temperatures were over 230°C showed that they exhibit better thermal stability.     

Orientation in the nitration of 3-phenyl-4-substituted furazans

The nitration of 3-phenyl-4-substituted furazans with various nitrating agents was investigated. It is shown that the orientation of the nitro group that is incorporated in the phenyl ring is determined by the substituent in the 4 position of the furazan ring, whereas the introduction of a furazan substituent in the phenyl ring lowers the reactivity of the latter. The corresponding dinitro derivatives can be obtained by means of acid mixtures.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 27–29, January, 1982.     

Pharmacophore mapping and electronic feature analysis for a series of nitroaromatic compounds with antitubercular activity

A five point pharmacophore was generated using PHASE for a series of nitroaromatic compounds and their congeners as antitubercular agents. The generated pharmacophore yielded significant 3D‐QSAR model with r² of 0.890 for a training set of 92 molecules. The model also showed excellent predictive power with correlation coefficient Q² of 0.857 for a test set of 31 compounds. The pharmacophore indicated that presence of a nitro group, a piperazine moiety, one aromatic ring feature and two acceptor features are necessary for potent antitubercular activity. The pharmacophore was supported by electronic property analysis using density functional theory (DFT) at B3LYP/3–21*G level. Molecular electrostatic profile of the compounds was consistent with the generated pharmacophore model, particularly appearance of localized negative potential regions near both the oxygen atoms of nitro group extending laterally to the isoxazole ring system/amide bond in the most active compounds. Calculated data further revealed that all active compounds have smaller LUMO energies located over the nitro group, furan ring, and isoxazole ring/amide bond attached to it. Higher negative values of LUMO energies concentrated over the nitro group are indicative of the electron acceptor capacity of the compounds, suggesting that these compounds are prodrugs and must be activated by TB‐nitroreductase. The results obtained from this study should aid in efficient design and development of nitroaromatic compounds as antitubercular agents. © 2009 Wiley Periodicals, Inc. J Comput Chem, 2010     

Synthesis and Properties of Furazanyl-Substituted Acetylenes and Diacetylenes

Compounds of the acetylene and diacetylene series, containing a furazan ring, were synthesized by alkylation of 3,4-diaminofurazan and nucleophilic substitution of the nitro group in 3-amino-4-nitrofurazan under conditions of phase-transfer catalysis.     

Investigation on the correlation between the interaction energies of all substituted groups and the molecular stabilities of nitro compounds

A model, similar to an isodesmic reaction, is for the first time presented in this paper for describing, defining, and calculating the interaction energies of the indirectly linked groups or atoms within one molecule. Its applications to nitro substitutes of methane, benzene, and cubane verify its validity for a separate group of closely related compounds by the reasonable correlation between the calculated interaction energies of all substituted groups and the molecular stabilities or experimental impact sensitivities. Comparing with some existing rules of assessing the molecular stability, this so-called interaction energy is calculated using a model considering the chemical structures, that is, the electronic environments of compounds, and can be well related with the stabilities of nitro compounds. All investigation results show that the so-called interaction energy is a new, quantitative, and useful tool to evaluate the stabilities of nitro compounds.     

A New Approach to the Synthesis of 2-Nitrobenzaldehyde. Reactivity and Molecular Structure Studies

 New approaches to the synthesis of 2-nitrobenzaldehyde by formation and selective isomer separation of 2-nitrophenyl-1,3-dioxolane and further hydrolysis are reported. In this route, the same acidic heterogeneous catalyst is used for 1,3-dioxolane formation and hydrolysis; it can be recycled several times without loss of efficiency. The ortho/meta isomers of 2-nitrophenyl-1,3-dioxolane can be separated by a combination of stereoselective crystallization and fractionated distillation. This new route reduces safety and environmental hazards in the synthesis of 2-nitro- and 3-nitro-benzaldehydes. The molecular structures of the nitro derivatives were confirmed by ¹H and ¹³C NMR spectroscopy. The results are in accordance with a non-coplanar conformer of the 2-nitro derivatives (2-nitrobenzaldehyde and 2-(2′-nitrophenyl)-1,3-dioxolane), where the nitro group is twisted with respect to the phenyl ring. In contrary, both the carbonyl and the nitro group are coplanar with the phenyl ring in 3-nitrobenzaldehyde. This result is consistent with the reactivity of the compounds.     

A New Approach to the Synthesis of 2-Nitrobenzaldehyde. Reactivity and Molecular Structure Studies

Summary.  New approaches to the synthesis of 2-nitrobenzaldehyde by formation and selective isomer separation of 2-nitrophenyl-1,3-dioxolane and further hydrolysis are reported. In this route, the same acidic heterogeneous catalyst is used for 1,3-dioxolane formation and hydrolysis; it can be recycled several times without loss of efficiency. The ortho/meta isomers of 2-nitrophenyl-1,3-dioxolane can be separated by a combination of stereoselective crystallization and fractionated distillation. This new route reduces safety and environmental hazards in the synthesis of 2-nitro- and 3-nitro-benzaldehydes. The molecular structures of the nitro derivatives were confirmed by ¹H and ¹³C NMR spectroscopy. The results are in accordance with a non-coplanar conformer of the 2-nitro derivatives (2-nitrobenzaldehyde and 2-(2′-nitrophenyl)-1,3-dioxolane), where the nitro group is twisted with respect to the phenyl ring. In contrary, both the carbonyl and the nitro group are coplanar with the phenyl ring in 3-nitrobenzaldehyde. This result is consistent with the reactivity of the compounds. Received January 22, 2001. Accepted (revised) July 18, 2001     

(n‐Nitrophenyl)acetonitrile,with n = 2, 3 and 4

The molecular structures of the three title nitro‐substituted phenyl­aceto­nitriles, C₈H₆N₂O₂, at 123 K show that the mol­ecules are linked together very differently. In the 2‐ and 4‐nitro compounds, there are both O?H and N_cyano?H interactions, whereas the crystal lattice of the 3‐nitro compound is essentially built up by O?H interactions. The O atoms seem to prefer the aromatic H atoms, while the cyano N atoms prefer the methyl­ene H atoms. The phenyl–nitro torsion angles are ?19.83 (13), ?5.69 (12) and ?2.88 (12)°, while the phenyl–cyano­methyl torsion angles are ?62.27 (12), ?147.99 (9) and ?16.75 (14)° in the 2‐, 3‐ and 4‐NO₂‐substituted compounds, respectively.