Reduction of Sulphur-containing Aromatic Nitro Compounds with Hydrazine Hydrate over Iron(III) Oxide-MgO Catalyst

Sulphur-containing aromatic amines were prepared efficiently in good to excellent yields by reduction of the corresponding sulphur-containing aromatic nitro compounds with hydrazine hydrate in the presence of iron（Ⅲ） oxide-MgO catalyst. The catalyst exhibited high activity and stability for the reduction of sulphur-containing aromatic nitro compounds. The yields of sulphur-containing aromatic amines were up to 91-99 % at 355 K after reduction for 1-4 h over this catalyst.

The evaluation of bond dissociation energies for NO2 scission in nitro compounds using density functional and complete basis set methods

By using the density functional theory （B3LYP） and four highly accurate complete basis set （CBS-Q, CBS-QB3, CBS-Lq, and CBS-4M）ab initio methods, the X（C, N, O）-NO2 bond dissociation energies （BDEs） for CH3NO2, C2H3NO2, C2H5NO2, HONO2, CH3ONO2, C2H5ONO2, NH2NO2 （CH3）2NNO2 are computed. By comparing the computed BDEs and experimental results, it is found that the B3LYP method is unable to predict satisfactorily the results of bond dissociation energy （BDE）; however, all four CBS models are generally able to give reliable predication of the X（C, N, O）-NO2 BDEs for these nitro compounds. Moreover, the CBS-4M calculation is the least computationally demanding among the four CBS methods considered, Therefore, we recommend CBS-4M method as a reliable method of computing the BDEs for this nitro compound system.

Preparation of Sulphur-containing Aromatic Amines by Reduction of the Corresponding Aromatic Nitro Compounds with Hydrazine Hydrate over Iron Oxide Hydroxide Catalyst

Sulphur-containing aromatic nitro compounds were rapidly reduced to the corresponding amines in high yields by employing hydrazine hydrate as a hydrogen donor in the presence of iron oxide hydroxide catalyst. It was worth noting that the catalyst exhibited extremely high activity. The reduction could be completed within 20-50 min and the yields were up to 97-99 %.

LOW-VALENT TITANIUM INDUCED REACTION OF CARBOXYLIC DERIVATIVES WITH NITRO COMPOUNDS

The intermolecular reaction of carboxylic derivatives with nitro compounds induced by titanium tetrachloride and zine powder was studied.

A New Reagent for the Reduction of Aromatic Nitro Compounds

Aromatic nitro compounds were reduced to the corresponding anilines by refluxing with potassium selenated borohydride (KBH2Se3) prepared from potassium borohydride and selenium in refluxed formamide.

Stereoselective Addition of N-Alkylhydroxylamines to α,β-Unsaturated Nitro Compounds

N-Alkylhydroxylamines have been shown to undergo a stereospecific cis addition to 1-phenyl-2 -nitropropene compounds, whereas the corresponding O-alkylhydroxylamines give no diastereoselectivity. The concerted addition mechanism was provided to explain the difference.

Morphological and heterojunctional engineering of two-dimensional porous Mo-Ni based catalysts for highly effective catalytic reduction of aromatic nitro compounds

Hydrogenation reactions play crucial roles on chemical synthesis and pollutant elimination.The improvement of the ability to activate reactants and increase of the contact probability between the catalysts and reactants are positive to improve the catalytic performance.Herein,we have reported the design of two-dimensional porous Ni-Ni_(3)N-Ni Mo N heterojunction sheets(2D Mo-Ni based nanosheets)for efficient catalytic hydrogenation of the aromatic nitro-compounds.The heterojunction interfaces provide plentiful active sites to improve the activating ability of the catalyst on the reactants.Additionally,the 2D porous structure facilitates not only the contact of catalytic sites with reactants but also mass transfer and diffusion,both of which are favorable to accelerating the hydrogenation process.As a result,the optimized sample of 2D Mo-Ni sheet exhibits good activity for the hydrogenation of aromatic nitro-compounds by converting 0.2 mmol/L(30 mL)of p-nitrophenol to p-aminophenol within 45 s with good recyclability.The activation energy and the reaction rate at 25℃ is 31.11 k J/mol and 0.0796 s^(-1),respectively,both of which surpass most of reported non-noble metal catalysts and rivals with most noble metal-based catalysts.The combination of late and early transition metals provides an innovative way to obtain outstanding catalysts for the hydrogenation.

Samarium-promoted Chemoselective Reduction of Aromatic Nitro Compounds in Ionic Liquid

bState Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, China The differently substituted aromatic nitro compounds were chemoselectively reduced by Sm/HOAc system in an ionic liquid medium to afford aromatic amines. Under these conditions the other substituents, such as -X, -CHO, -COOH, -CN, -NHTos and -alkyl, remained intact. The notable advantages of this reaction are its mild conditions, simple operation, short reaction time, high yields and easy recycling of ionic liquid.

Michael Addition Reaction of Fluorinated Nitro Compounds

The Michael addition reactions of fluorinated nitro compounds with electron deficient olefins to give γ-fiuoro-γ-nitro-esters, nitriles and ketones which bear a fluorinated quaternary carbon center were reported. The reactions were promoted by TMG, affording the desired adducts in acceptable to good yields.

Tandem synthesis of tertiary amines using graphene encapsulated Ni nocatalyst via nitro compounds hydrogenation and primary amine methylation

Development of the economic, environmentally friendly synthesis of amines from nitro compounds remains important and challenging. In this work, the graphene shell encapsulated none noble Ni-based catalysts were successfully designed and synthesized via an environmentally friendly method using H2O or Et OH as solvent. These fresh and recycling catalysts were characterized by X-ray diffraction and X-ray photoelectron spectroscopy. For the nitro compounds hydrogenation, Ni@C-600-H2O exhibits the best catalytic activity to achieve 100 mol/mol conversions of nitrobenzene and 99% selectivity of aniline under mild reaction conditions of 1.0 MPa H2and 60°C.Many halogen-substituted, olefin substituted nitro compounds and aliphatic nitro compounds were investigated and desired products were obtained in excellent selectivity. What is more, the catalyst had excellent stability and could be recycled 13 times without any significant loss in selectivity and activity. Furthermore, we also reported the methodology for tertiary amines synthesis using Ni-based catalyst via one-pot, cost-effective tandem combination reaction with nitrobenzene hydrogenation and amines N-methylation.

Low-valent titanium induced reductive cyclization of nitro compounds and aliphatic ketones:facile synthesis of 3,4-dihydro-(2H) -1,2,4-benzothiadiazine-1,1-dioxides

The intermolecular reductive cyclization of o-nitrobenzene-sulfonamides with aliphatic ketones induced by TiCl4/Sm system was studied and a series of 3, 3-disubstituted-3,4-dihydro(2H)-1,2, 4-benzothiadiazine-1,1-dioxides were synthesized in moderate to high yields under mild and neutral conditions.

Photocatalytic Reduction of Nitro Compounds Using TiO2 Photocatalyst by UV and Vis Dye-sensitized Systems

Nitro-aromatic compounds can be photocatalytically reduced into the corresponding amine-aromatic com- pounds using TiO2 as a photocatalyst in the UV/TiO2/holes scavenger and Vis/TiO2/dye-sensitized systems. In the UV/TiO2/holes scavenger system, reaction substrate alcohols such as methanol could be used as the holes scavengers, and in the Vis/TiO2/dye-sensitized system, substrate alcohols could be oxidized to the corresponding aldehydes with high selectivity. When methanol was used as the holes scavengers and the illumination time was 6 h, 87.2% ofp-nitrotoluene could be photocatalytically reduced into p-toluidine. In the Vis/TiO2/dye-sensitized system, the effect of aromatic alcohols for the photocatalytic reduction of nitrobenzene was better than that of other alcohols At the same time, aromatic alcohols can be easily oxidized, and the production efficiencies of the corresponding aldehydes were higher than those of other alcohols. The possible reaction mechanisms were also proposed.

Anaerobic Biotransformation of Nitro-Compounds to Amines by Bovine Rumen Fluid

Microorganims of the bovine rumen fluid biocatalyzed the reduction of nitro-compound substrates to yield the respective amines. This enzymatic process, using ruminal contents, has rarely been reported in associa- tion with the bioreduction of nitro groups. The biotransformation reactions catalyzed by this system were de- pendent of both the electronic characteristics and the area/volume of the nitro-substrates confirming the processes are enzymatic. The semi-preparative scale biotransformation went by in good yield showing the rumen fluid may be employed in the synthesis of amines under very mild conditions and, moreover, it may have application in the bioremediation of nitro-compounds.

STUDIES ON THE ADSORPTION OF PHENOLIC COMPOUNDS ON A PS-BASED RESIN MODIFIED BY NITRO FUNCTIONAL GROUPS

A new adsorbent (JN-01) was prepared by modifying resin NDA-1800 with nitro functional groups.The adsorption capacities of resins XAD-4,NDA-1800 and JN-01 were investigated,and the results indicated that the modified resin JN-01 was much better in adsorbing phenol,p-nitrophenol and p-cresol.The adsorption capacities of the resin JN-01 were higher than those of the resins XAD-4 and NDA-1800 within a temperature range of 283-323 K,which might be attributed to the higher surface area and the partial polarity o...

Immobilized silver nanoparticles on silica gel as an efficient catalyst in nitroarene reduction

Nanoparticles have properties that can be fine-tuned by their size as well as shape.Hence,there is significant current interest in preparing nano-materials of small size dispersity and to arrange them in close-packed aggregates.This letter describes a way of synthesising silver nanoparticles and their protection to aggregate by silica gel.The combination of catalytic quantities of immobilized silver nanoparticles with reductive ability of NaBH_4 efficiently reduces aromatic nitroarenes to the corresponding amines in aqueous medium.Noteworthy is that highly chemoselective reactions were achieved in the presence of other functional groups such as halogen and carboxylic acid groups.The silver particles immobilized on silica gel are stable in the presence of oxygen for several months.

基于荧光淬灭传感技术检测三硝基甲苯的研究

目前针对常见爆炸物三硝基甲苯(TNT)的检测越来越受到重视。本研究采用低成本的芴基发绿光共轭聚合物(FGEP)研制荧光淬灭传感器用于检测TNT。实验研究了FGEP在不同溶液浓度下形成的不同厚度薄膜对TNT淬灭的效率,实验结果表明浓度为0.5 mg/mL (厚度为19.50 nm)的样品薄膜在TNT蒸气中淬灭效率最大达到71.71%,基于此淬灭效率最高的样品薄膜的研究发现:该薄膜对TNT的响应具有良好的可逆性;激发光强度为16.5mW时,荧光淬灭效率最佳;最后开展了样品在TNT作用下与光漂白作用下的实验研究。研究结果为后续实现一种低成本、易于制备、可重复性高且有利于工程化的爆炸物传感器提供了一定基础。

典型二元硝基化合物的热危险性分析

文章选择了2,4-二硝基苯胺、2,6-二硝基苯胺和1,4-二硝基苯3种典型的二元硝基化合物作为实验对象,通过差示扫描量热实验(DSC)、热重实验(TG/DTG)和绝热加速量热实验(ARC)分析了3种物质的分解过程,获取了热危险性数据和动力学参数。结果表明,3种物质的分解过程均可分为三个阶段,即能量缓慢释放阶段、能量积聚阶段和能量爆发阶段,在物质储运过程中需要严格控制温度,防止物质进入能量爆发阶段;3种物质的危险性程度由高到低依次为2,4-二硝基苯胺、2,6-二硝基苯胺、1,4-二硝基苯。

硝基和尿基复合肥装置工艺特点综述

本文综述了硝基和尿基复合肥装置的工艺特点,包括原料选择、工艺流程、设备配置、生产控制等方面。文章首先介绍了硝基、尿基复合肥的定义及其在农业生产中的重要地位,然后详细阐述了硝基、尿基复合肥的生产工艺及其特点,分析了工艺中的关键环节和技术难点,最后指出了工艺改进的方向和未来发展前景。

芳香族硝基化合物自加速分解温度的定量结构-性质关系

针对芳香族硝基化合物生产、运输以及储存过程中引发的重特大燃爆事故,采用试验及模型计算等方式对其自加速分解温度(SADT)进行获取,并提出一种基于定量结构-性质关系(QSPR)的理论预测方法。通过绝热加速量热试验获取18种芳香族硝基化合物的热力学和动力学参数,以此计算得到25 kg标准包装下物质的自加速分解温度。应用多元线性回归(MLR)和人工神经网络(ANN)等机器学习方法分别构建相应的预测模型,最终验证并比较两种模型的拟合能力、鲁棒性和预测能力。结果表明:芳香族硝基化合物对应MLR模型和ANN模型的相关系数分别为0.893和0.975,ANN模型在匹配度方面明显优于MLR模型。

木质素磺酸钠荧光膜的制备及其在硝基爆炸物检测中的应用

以木质素磺酸钠(LS)为原料,聚乙烯醇为黏合剂,制备了木质素磺酸钠荧光膜。通过荧光光谱仪和激光粒度分析仪对LS的形态和光学性质进行了分析,研究了硝基化合物和无硝基化合物对LS的荧光猝灭作用及猝灭机理,并将木质素磺酸钠荧光膜应用于硝基爆炸物的检测。研究结果表明:LS随着制备溶剂中乙醇体积分数的增加,其荧光发射峰强度增加,分子之间发生缓慢聚集,且聚集体颗粒变大,具有聚集诱导发射(AIE)性质;硝基苯和对硝基苯酚均对LS的荧光猝灭程度高达90%,间二硝基苯对LS的荧光猝灭程度也有56%;苯、甲苯、苯酚、对苯二甲酸、对苯二甲醛和邻苯二甲醛等无硝基化合物对LS的荧光猝灭作用几乎没有。LS对硝基苯、间二硝基苯和对硝基苯酚等硝基化合物显示出专一、特异的高灵敏检测性能,该现象主要由光诱导电子转移机制造成的。浸泡过硝基苯/乙醇溶液、间二硝基苯/乙醇溶液和对硝基苯酚/乙醇溶液的木质素磺酸钠荧光膜的荧光猝灭程度分别为89%、78%和100%。将硝基化合物溶液在荧光膜上涂写,在日光下观察不到笔迹存在,而在紫外光下能观察到笔迹部分有明显的荧光猝灭现象。