金纳米修饰毛细管电泳分离氨基苯甲酸

报道了一种金纳米修饰毛细管电泳分离、测定氨基苯甲酸的新方法。采用制备的金纳米进行了石英毛细管修饰。探讨了修饰金纳米浓度、修饰时间以及缓冲溶液加入一定浓度的金纳米对三种氨基苯甲酸分离和测定的影响,优化了分离电压、酸度以及缓冲溶液浓度等实验条件。结果表明金纳米的存在,显著的改进了氨基苯甲酸分离的选择性,增强了分离效率。在优化的实验条件下,进行了邻、间、对三种氨基苯甲酸的分离和测定。线性浓度范围为0.5–40 µg·mL,相关系数0.9978-0.9992。检测限(S/N = 3) 为0.1-0.5µg·mL。     

两种新型氯代荧光素探针染料的合成和表征

研究了两种具有空间连接链的新型氯代荧光素探针染料4',5'-二氯-6-(5-羧基戊氨基羰基)荧光素和2',7'-二氯- 6-(5-羧基戊氨基羰基)荧光素的合成. 以氯代间苯二酚和苯三酸酐为起始原料经7步反应得到了目标化合物, 产率良好. 测定了目标产物的荧光性能, 结果显示该化合物具有很高的荧光量子产率, 与荧光素母体相比其激发和发射波长明显向长波方向移动. 所得产物结构经1H NMR, IR, MALDI-TOF MS以及元素分析进行了表征.     

高效液相色谱法测定水体中的痕量一氧化氮

基于4,5-二氨基荧光素与一氧化氮（NO）反应生成高荧光三唑荧光素的原理，建立了一种测定水体中溶解NO的高效液相色谱方法。通过不同流动相（乙腈∶磷酸盐缓冲溶液）配比实验和色谱柱温度梯度实验，确定了该方法测定水体中NO的最佳实验条件：流动相配比为乙腈∶磷酸盐缓冲溶液=8∶92(V/V)；柱温为25℃。在优化条件下，测得NO浓度与荧光强度在0.33～3.32 nmol/L和13.3～266 nmol/L范围内具有良好的线性关系，检出限为90 pmol/L，相对标准偏差为5.1%，平均加标回收率为122.4%。方法可用于测定可口可乐、植物饮料、海水和日本星杆藻藻液中的NO浓度。     

萤火虫氨基氧化荧光素相似物作为有机发光二极管材料的理论研究

由于萤火虫荧光素具有发光效率高,能发出从绿色到红色多种颜色光的特点使其在有机发光器件领域存在巨大的应用潜力.为了探索结构和性质的关系,我们用苯并吡喃、联苯、联吡啶、菲、邻二氮杂菲、芴和晕苯取代氧化荧光素中的苯并噻唑部分,设计了一系列氨基氧化荧光素相似物.本工作用密度泛函理论和含时密度泛函理论方法对这些化合物进行了一系列光电性质的研究.计算结果表明,含有氮原子的氨基联吡啶氧化荧光素(BPAOL)和氨基邻二氮杂菲氧化荧光素(PMAOL)与含有碳原子的氨基联苯氧化荧光素(BIAOL)和氨基菲氧化荧光素(PHAOL)比较具有较小的最高占据分子轨道(HOMO)和最低非占据分子轨道(LUMO)轨道能量及更大的电离能(IP)和电子亲和势(EA)值.化合物氨基氧化荧光素(AOL),BIAOL,BPAOL,PHAOL,PMAOL,氨基芴氧化荧光素(FLAOL)和氨基晕苯氧化荧光素(COAOL)可以作为电子注入/传输材料.AOL、PHAOL、FLAOL和COAOL可以作为蓝色发光材料.     

氨基苯甲酸的HPLC分离研究进展

综述了氨基苯甲酸异构体的ＨＰＬＣ分离方法，总结了各种分离方法的影响因素，为以后的分析工作提供了理论基础。     

硝基苯甲酸与氨基苯甲酸六种异构体的HPLC分离研究

采用Kromasil C18(4.6×200mm)柱同时分离了硝基苯甲酸与氨基苯甲酸六种异构体,在不到7min的时间内,硝基苯甲酸与氨基苯甲酸异构体在0.1～1.0g/L 浓度范围内,得到了良好分离.     

2,4-/2,6-二氨基甲苯在D151树脂上的吸附分离

从10种树脂中筛选出D151树脂对2,4-二氨基甲苯和2,6-二氨基甲苯的吸附分离及其热力学性质进行了研究。 测定了吸附等温线,Freundlich模型对实验的拟合度大于Langmuir模型,其相关系数大于0.99。 热力学研究结果表明,在293～313 K条件下,初始质量浓度为60～80 g/L时,2,4-二氨基甲苯的吸附焓变为-4.3490～-5.7558 kJ/mol,自由能变为-0.2911～-1.0346 kJ/mol,吸附熵变为-12.965～-16.150 J/(mol·K);而2,6-二氨基甲苯的吸附焓变为-2.9645～-3.6054 kJ/mol,自由能变为-0.1610～-0.6384 kJ/mol,吸附熵变为-7.939～-11.005 J/(mol·K)。 进一步研究了D151树脂对二氨基甲苯的动态吸附分离,可以将2,6-二氨基甲苯含量从20%提高至99.93%,将2,4-二氨基甲苯含量从80%提高至99.42%。     

氨基苯磺酸和氨基萘磺酸在反相离子对色谱和离子色谱中分离行为的比较

 本文考察了氨基苯磺酸和氨基萘磺酸染料中间体在反相离子对色谱和离子色谱中的分离行为，结果表明一些异构体在反相色谱中的保留顺序与离子色谱中的顺序发生颠倒。静电作用力在离子色谱中对保留值的贡献比在反相离子对色谱中对保留值的贡献要大，而疏水作用力在反相离子对色谱中对保留值的贡献却较在离子色谱中对保留值的贡献要大。离子对色谱更有利于有机离子的分离分析。     

反相色谱法分离氨基苯磺酸和氨基萘磺酸离子性化合物的研究

本文讨论了反相色谱分离氨基苯磺酸,氨基萘磺酸离子性化合物的可行性。所应用的实验条件为检测波长254nm,流动相为10mmol/L 磷酸二氢钠缓冲液(pH=6.98),固定相是C_(18)担体。还讨论了分子结构对保留值的影响。     

异硫氰酸荧光纳米复合粒子的研制与应用

采用改进的St ber法制备了二氧化硅外壳的纳米复合荧光粒子。利用异硫氰酸荧光素(FITC)与3-氨基丙基三乙氧基硅烷(APTEOS)反应制备前驱体,再用正硅酸乙酯(TEOS)在一定的条件下水解与缩合,制备有机-无机纳米复合荧光颗粒,利用透射电子显微镜(TEM)测试表明,此纳米复合颗粒呈球形、大小均一,直径约为70 nm。制备的纳米复合荧光粒子经过多次水洗后,仍有较强的荧光特性,有效地防止FITC泄露。用激光共聚焦显微镜观测纳米复合荧光粒子标记的牛血清白蛋白(BSA),可以明显看出BSA上的绿色荧光。     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.