氮唑并均三嗪类化合物的合成研究进展

氮唑并均三嗪类化合物具有抗增殖、抗氧化、抗病毒、抗肿瘤等多种生物活性,引起了药物化学家及相关工作者的特别关注,所以关于氮唑并均三嗪类化合物的合成方法成了研究热点.从四氮唑并均三嗪、三氮唑并均三嗪、二氮唑并均三嗪这三个方面综述了这类化合物的合成方法,最后对这类化合物合成方法中存在的问题进行了讨论,并对未来的发展进行了展望.     

燃煤电厂异相凝并飞灰重金属淋滤特性

采集了燃煤电厂的异相凝并后飞灰,分析了其物理化学特性。并通过淋滤实验研究了飞灰中重金属As、Se、Pb的环境稳定性。结果表明,凝并飞灰的粒径峰值为138.04μm,而粉煤灰为60.26μm;凝并后细颗粒凝聚成了较大的颗粒;凝并飞灰中重金属As、Se、Pb含量均高于同工况下粉煤灰中的含量,且后序脱硫环节所产生石膏中重金属的含量有所下降;批淋滤实验研究结果表明,凝并飞灰中的重金属浸出能力受淋滤液的pH值影响较大,温和环境和碱性条件抑制了As的浸出,酸性和碱性条件抑制了Se的浸出,而碱性条件抑制了Pb的浸出。柱淋滤实验研究结果表明,在酸性溶液和水溶液中,凝并飞灰的重金属浸出能力均受到了抑制。     

复合聚并协同脱除燃煤颗粒物及颗粒态重金属的中试研究

燃煤颗粒物和其上富集的As、Se、Pb等重金属排入大气后危害环境和人体健康。本研究开发以湍流聚并、壁面回流吸附为原理的复合聚并器,研究了聚并前后对颗粒物和颗粒态重金属的聚并效果。首先采用数值模拟方法综合考虑压力损失、速度均匀性和颗粒物聚并效果,优选了折叶片作为复合聚并器的叶片类型。随后进行了不同流量的颗粒物聚并中试研究,发现复合聚并器对PM₁的聚并率可达32.84%,随着流量从11.1 m/s增加到17.6 m/s,PM_2.5聚并率呈现一定下降趋势,说明了流量增加导致颗粒停留时间缩短和颗粒物聚并率的下降。通过对比聚并前后颗粒物中As、Se、Pb的浓度变化,发现聚并过程增强了对气态重金属的吸附,也会聚集富含重金属的纳米级颗粒物,从而造成PM₁中重金属浓度的增加。聚并后PM₁内的As、Se、Pb绝对浓度的降低,显示了复合聚并器对颗粒物和颗粒态重金属的协同脱除效果。     

4,6-2,1,3-苯并噻二唑:一种新的聚合物光电功能材料构筑砌块和多性能调节剂

采用Suzuki缩合聚合方法,将4,6-苯并噻二唑单元引入到聚合物中,合成了4,6-苯并噻二唑-咔唑共聚物P1,研究了其光学性质和电化学性质.结果表明,与4,7-位结构类似物(HBC)相比,P1在Mn=12000时仍易溶于甲苯,二氯甲烷等一般的有机溶剂中;其薄膜状态时的紫外吸收光谱和光致发光光谱分别蓝移78和43 nm;光学带宽和电化学带宽分别增大0.35和0.40 e V,而循环伏安曲线的形状不变;说明4,6-位苯并噻二唑单元的引入,有效地改善了苯并噻二唑类聚合物的溶解性能,调节了光电性能,但保留了苯并噻二唑单元优异的电化学稳定性和可逆性.4,6-位苯并噻二唑单元的引入为实现苯并噻二唑类聚合物材料的多性能调节提供了一种新的手段和方法.     

亚微米尘粒电凝并的分形研究

在对电场中亚微米尘粒运动及凝并规律进行理论分析的基础上,应用分形生长理论建立了亚微米粒子电凝并过程的分形生长数学模型,再现了凝并体的分形结构,确定了凝并体的分形维数及其对除尘效率的影响.分形维数可定量描述尘粒凝并的难易程度,研究表明,对直径为0.01～1 μ m的球形尘粒,其凝并体具有较大的分形维数2.725432,随着粉尘粒度组成的变化,分形维数也将发生改变.分维数越大,凝并体结构越不规则,向空间扩展生长的能力越强,尘粒越容易聚集凝并,除尘器效率越高.     

苯并(a)芘的高效液相色谱荧光分析法的研究Ⅰ

本文对苯并(a)芘的荧光性质进行了研究,建立了苯并(a)芘的高效液相色谱分离荧光检测法.并用于环境水样分析,结果令人满意。     

苯并环丁烯类化合物的合成

苯并环丁烯类化合物是一类具有优异特性的聚合物材料,它具有极其广泛的用途和商业开发前景。本文给出了当前苯并环丁烯单体、衍生物和聚合物的合成方法,并简要介绍了苯并环丁烯类化合物在合成研究和工程中的应用。     

开发校本课程培养学生的环保意识——泾河平凉段水污染情况的调查研究

平凉师范化学与环保课程于2005-2008年开设以来,结合教学,并多次组织学生对泾河平凉段水污染情况进行了实地考察,采集水样,并对采集的水样进行了简单的化学分析。通过调查,明确了泾河河水被污染的原因和造成的危害,并提出了治理泾河污染的一些建议,同时培养了学生的环境保护意识。     

新型聚苯并咪唑的研究进展

聚苯并咪唑是一类重复基元含苯并咪唑结构的芳香杂环聚合物,具有耐高温、耐腐蚀、高机械强度、高阻燃性等特点,被广泛应用于耐高温质子交换膜、防火阻燃及航空航天领域。近年来,各种不同结构的新型聚苯并咪唑不断被合成报道,新颖的结构基元赋予聚苯并咪唑改善的溶解性、提升的抗氧化性、高的酸负载水平及多孔特性,进一步拓展了聚苯并咪唑在吸附分离及燃料电池方面的应用。综述了新型聚苯并咪唑的研究进展,重点介绍了新型聚苯并咪唑的结构种类及其功能应用,旨在促进聚苯并咪唑研究的发展。     

Monte Carlo方法在高分子科学中的应用

介绍了Monte Carlo方法的历史及其特点,并描述了它在现代高分子科学研究中的广泛应用情况,并对其前景作了一些展望。     

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.     

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.     

Selective syntheses of 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones via temperature-dependent Rh(II)-carbenoid-mediated 2H-azirine-ring expansion

The Rh(II)-catalyzed reaction of 2-carbonyl-substituted 2H-azirines with ethyl 2-cyano-2-diazoacetate or 2-diazo-3,3,3-trifluoropropionate provides an easy access to 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones. These compounds can be selectively prepared from the same starting material using temperature as the only varied parameter. The 2-azabuta-1,3-diene intermediate, a common precursor for both heterocyclic products, isomerizes into 2H-1,3-oxazine under kinetic control, while 1H-pyrrol-3(2H)-one is the sole product of the reaction at elevated temperatures. According to DFT-calculations a one-atom oxazine ring contraction involving ring-opening to a 2-azabuta-1,3-diene intermediate, followed by a 1,5- and 1,2-prototropic shift leads to the consecutive formation of imidoylketene and azomethine ylide, which then further undergo cyclization to the pyrrole derivative.     

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.