2-氨基-3-硝基吡啶和2-氨基-5-硝基吡啶的EI/MS/MS分析

2 氨基 3 硝基吡啶和2 氨基 5 硝基吡啶的一级质谱图接近,单纯通过一级质谱图较难区分这两种异构体,利用离子阱质谱的串联质谱技术对2 氨基 3 硝基吡啶和2 氨基 5 硝基吡啶在离子阱内以He作碰撞气进行碰撞诱导裂解,所得的二级质谱图表明,两者之间存在明显的差别,可用于2 氨基 3 硝基吡啶和2 氨基 5 硝基吡啶的鉴别。     

2-氨基-5-硝基吡啶在基体辅助激光解吸/电离质谱法测定核酸分子中的应用

报道以2-氨基-5-硝基吡啶为基体用基体辅助激光解吸/电离质谱法(MALDI-MS)对DNA样品进行测定并研究它们的激光质谱特征,结果表明,2-氨基-5-硝基吡啶是DNA的一高效基体.用柠檬酸铵和NH_4~+阳离子交换树脂除去试剂和样品中的碱金属离子,能显著地提高解吸/电离DNA分子的效率.     

一种有效制备2-氨基-3,5-二硝基-6-氯吡啶及其衍生物的方法

研究了2-氨基-3,5-二硝基-6-氯吡啶(4)及其衍生物的制备新方法.以廉价易得的2,6-二氯吡啶(1)为起始原料,通过硝化、氨化、硝化反应步骤得到中间体2-氨基-3,5-二硝基-6-氯吡啶(4),再与氨、叠氮化钠等亲核试剂反应分别得到2-氨基-3,5-二硝基吡啶-6-取代衍生物5~7.研究表明该方法具有原料便宜易得、后处理操作简单和产品纯度高等优点.     

2-氨基-5-硝基吡啶水杨醛Schiff碱的合成及与DNA的相互作用

合成了含吡啶环的2-氨基-5-硝基吡啶水杨醛Schiff碱(HL),产物经红外光谱、质谱、核磁共振波谱进行了确认。通过电子光谱法和分子发光光谱法研究了HL与鲱鱼精DNA(hs-DNA)的相互作用。结果表明：HL可引起hs-DNA 260 nm处特征吸收峰的红移和明显的减色效应,HL可竞争溴化乙锭(EB)与DNA的结合,把与hs-DNA结合的EB释放出来,令EB-DNA体系发生静态荧光猝灭。热力学计算表明,氢键和范德华力是两者间主要作用力类型,HL以嵌插方式与hs-DNA结合。     

2-氨基-6-甲氧基-3-硝基吡啶的合成

以2-氯-5-硝基吡啶为原料,经甲氧基化反应得2-甲氧基-5-硝基吡啶(2),2再与液氨/高锰酸钾进行氨化反应制得2-氨基-6-甲氧基-3-硝基吡啶,总收率77%。     

高效液相色谱法测定吡啶、2-氨基吡啶、2-甲基吡啶和2-吡啶甲酸

建立了以磷酸氢二钾-磷酸盐缓冲溶液中添加甲醇为流动相，以反相高效液相色谱同时测定吡啶、2-氨基吡啶、2-甲基吡啶和2-吡啶甲酸的新方法。在流动相为甲醇-0．1mol／L磷酸氢二钾和磷酸缓冲溶液、pH为6．0的最佳条件下，吡啶、2-氨基吡啶、2-甲基吡啶和2-吡啶甲酸的加标回收率分别为98．2％～102．1％、99．1％～101．3％、97．8％～100．7％和99．1％～102．4％；线性范围分别为20～980、18～913、19～943和18～902mg／L；检出限分别为2．0、1．8、1．9和1．8mg／L。本法可同时测定电氧化2一甲基吡啶过程中电解液。     

5-氨基-6-硝基-[1,2,5]噁二唑并[3,4-b]吡啶-1-氧化物的合成新方法

以2,6-二氯吡啶为起始原料, 经肼基化、还原、硝化、Nietzki-Dietschy环合4步反应得到5-氨基-6-硝基-[1,2,5]噁二唑并[3,4-b]吡啶-1-氧化物。 结合反应机理讨论了还原、硝化、Nietzki-Dietschy环合反应的影响因素,获得了合成5-氨基-6-硝基-[1,2,5]噁二唑并[3,4-b]吡啶-1-氧化物的最佳工艺条件,目标产物的总收率为59.2%。 用1H NMR、MS和IR谱对5-氨基-6-硝基-[1,2,5]噁二唑并[3,4-b]吡啶-1-氧化物的结构进行了表征。     

2,6-二氨基-3,5-二硝基吡啶-1-氧化物的合成新方法

研究了2,6-二氨基-3,5-二硝基吡啶-1-氧化物(ANPyO)的合成新方法. 以2,6-二氨基吡啶为起始原料, 经酰基化、N-氧化、硝化三步反应得到ANPyO, 总收率为75%. 测试了ANPyO的爆速、爆压、DSC, 以及电火花感度和落锤感度, 同1,3,5-三氨基-2,4,6-三硝基苯(TATB)的性能进行了对比, 结果表明ANPyO综合性能和TATB基本相当. 用1H NMR, MS和红外光谱对ANPyO及其中间体结构进行了表征.     

新试剂4，4'-(2-氯-4-硝基重氮氨基)联苯与氯化十六烷基吡啶显色反应的研究

研究了4,4'-(2-氯-4-硝基重氮氨基)联苯与阳离子表面活性剂氯化十六烷基吡啶发生显色反应,提出了光度法测定氯化十六烷基吡啶的新方法。实验结果表明,在碱性介质中,4,4'-(2-氯-4-硝基重氮氨基)联苯与氯化十六烷基吡啶形成1：2紫红色离子缔合物,最大吸收波长位于570 nm处,表观摩尔吸光系数为2.16×104...     

聚-2-氨基吡啶电化学合成及性质

报导了在 0.43 mol•dm－3 C6H6N2和0.01 mol•dm－3 NaOH中用循环伏安法合成聚-2-氨基吡啶. 聚-2-氨基吡啶在1.0 mol•dm－3 ZnCl2(pH=4.99)溶液中的循环伏安图上有三对氧化-还原峰.旋转环-盘实验的结果表明,在 2-氨基吡啶聚合的初期有中间体生成.由红外光谱可知，聚-2-氨基吡啶具有头-尾相接的结构.聚-2-氨基吡啶平均粒子大小约893 nm， 平均粒子间距约 255 nm. 由聚-2-氨基吡啶正极和锌负极及2.5 mol•dm－3 ZnCl2溶液和 3.0 mol•dm－3 NH4Cl (pH=5.5) 溶液构成的电池，其放电曲线类似于Li-SOCl2, 放电曲线的中间区域非常平稳.     

The analysis of 1-propanol and 2-propanol in humid air samples using selected ion flow tube mass spectrometry

Following the observation that propanol is present in the breath samples of cystic fibrosis (CF) patients infected by Pseudomonas aeruginosa (PA), a study of the reactions of H(3)O(+), NO(+) and O(2) (+.) with 1-propanol and 2-propanol has been conducted using selected ion flow tube mass spectrometry (SIFT-MS). In this study the number and the distribution of the product ions from NO(+) reactions with the two propanol isomers under humid air conditions were able to differentiate between the two isomers. The reaction mechanisms and the structures of the product ions for these reactions, especially those with H(3)O(+) and NO(+), have been proposed. As an example, 2-propanol was shown to be present in a breath sample from one CF patient infected with PA, and also in a PA isolate from another CF patient grown on Pseudomonas-selective media. The results of this study allow an analytical procedure to be advanced for the analysis of the two propanol isomers, which can also be utilised in other applications.     

FT-Raman and FT-IR spectra, vibrational assignments and density functional studies of 5-bromo-2-nitropyridine

The Fourier transform Raman and Fourier transform infrared spectra of 5-bromo-2-nitropyridine were recorded in the solid phase. The equilibrium geometry, natural atomic charges, harmonic vibrational frequencies, infrared intensities and Raman scattering activities were calculated by density functional B3LYP method with the 6-311++G(d,p) basis set. The scaled theoretical wavenumbers showed very good agreement with the experimental values. A detailed interpretations of the infrared and Raman spectra of 5-bromo-2-nitropyridine is reported on the basis of the calculated potential energy distribution (PED). The theoretical spectrograms for the Raman and IR spectra of the title molecule have been constructed.     

2-氨基-5-硝基吡啶乙酸根桥联双核铜配合物的合成和晶体结构

2-氨基-5-硝基吡啶与Cu(CH3COO)2反应生成一个新的乙酸根桥联的双核铜配合物[Cu(CH3COO)2(C5H5N3O2)]2.2H2O.该配合物中,铜原子与一个吡啶环上N原子和四个乙酸根上O原子配位形成五配位的四方锥构型.其晶胞参数为:单斜晶系,空间群P21/c,a=0.834 5(8),b=2.001(2),c=0.808 1(8)nm,β=96.734(4)°,V=1.340(2)nm3,Z=2,Mr=657.37,Dc=1.629 g/cm3,F(000)=652,μ=1.663 mm-1,R1=0.060 4,wR2=0.126 4.电子吸收光谱在207 nm处有吸收;电子发射光谱在419 nm处有发射峰.并用IR和元素分析对配合物进行了表征.     

Studies in the heterocyclic series. XI. Reactions of 2-Amino-3-hydroxypyridine with 2-Chloro-3-nitropyridine

The reactions of 2-amino-3-hydroxypyridine and 2-chloro-3-nitropyridine in various solvents and in the presence of certain catalysts were studied. A dilute acid-catalysed procedure led to a 45% yield of 3-hydroxy-3-nitro-2,2-dipyridylamine which was also obtained by refluxing in alcoholic potassium hydroxide for several hours. The diarylamine was converted to 1,9-diazaphenoxazine by base-catalysed intramolecular condensation in refluxing DMSO. The same diazaphenoxazine was obtained directly by prolonged base-catalysed reaction of the starting pyridine compounds in DMSO. From a study of the infrared spectrum of the diarylamine precursor, it was found that strong NHO hydrogen bonding is responsible for the failure of the cyclization step in either aqueous or alcoholic base. This problem was overcome by the use of DMSO as the reaction solvent. Structural assignments were made by a study of their ultraviolet, infrared, nmr and mass spectra and the mechanistic pathways were also discussed.     

Indolic urinary melanogens: separation and identification by gas chromatography with selected-ion monitoring mass spectrometry of 5-hydroxy-6-methoxyindole-2-carboxylic and 5-methoxy-6-hydroxyindole-2- carboxylic acids.

Two isomeric urinary melanogens, 5-hydroxy-6-methoxyindole-2-carboxylic acid and 5-methoxy-6-hydroxyindole-2-carboxylic acid, have been separated by gas chromatography with selected-ion monitoring mass spectrometry. After chemical synthesis of one of these two isomers, 5-methoxy-6-hydroxyindole-2-carboxylic acid, and the establishment of the mass spectrum of its trimethylsilylated derivative, a 30-ml sample of a melanotic 24-h urine was adjusted to pH 1 and extracted twice with 10 ml of ethyl acetate. The extract was evaporated to dryness and the residue derivatized with methyl-8, followed by Tri-Sil/TBT. Silylated derivatives were analysed by gas chromatography with selected-ion monitoring mass spectrometry. The mass spectrum of the 5-methoxy-6-hydroxyindole-2-carboxylic acid allowed the determination of the retention times of both isomers.     

Electronic spectra and structure of methyl derivatives of 4-nitropyridine N-oxide

The UV spectra of seven methyl derivatives of 4-nitropyridine N-oxide in ethanol have been examined. The electronic spectra were calculated by a modified INDO method. Transition energies, intensities and assignments were compared with UV spectra. Spectroscopic manifestations of intramolecular interaction indicate that methyl groups modify the electronic interaction between the N-oxide and NO₂ groups mainly through a steric strain.Department of Organic Chemistry, University of Economics, Pl-53342 Wroclaw, Poland. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 786–793, June, 2000.     

磷原子团簇同分异构体的理论研究I:P5+、P5-和P5的预测

由激光产生的磷原子团簇正离子的质谱图中呈现很强的 P5 和 P5- 谱峰。使用分子图形学方法设计出 9种可能的同分异构体 ,对其中性及正负离子分子进行了分子力学、PM3半经验量子化学和 ADF密度泛函优化。在磷原子团簇模型中 ,磷原子采用 2、3或 4配位方式成键。从各异构体成键能量的比较可得知 ,最稳定的 P5 构型是四方锥的结构 ,最稳定的 P5-构型是平面五边形的结构 ,而最稳定的 P5构型是在最稳定的 P4的增加一个 2配位原子所生成的结构