基于磁性共轭微孔聚合物的超高效液相色谱-串联质谱法测定果蔬中7种有机磷杀虫剂

建立了基于磁性共轭微孔聚合物的磁固相萃取-超高效液相色谱-串联质谱（UPLC-MS/MS）测定果蔬中7种有机磷杀虫剂的方法。将亚苯基亚乙炔基修饰的Fe₃O₄与1,3,5-三溴苯、1,3,5-三乙炔苯反应,制备磁性共轭微孔聚合物,材料能有效吸附共轭结构的有机磷杀虫剂,并在外磁场中实现便捷磁分离。方法的检出限（LOD）为0.12~5.0 ng/kg,加标回收率为80.8%~125%,相对标准偏差（RSD）小于6%（n=5）。方法应用于分析市场上果蔬样品中7种有机磷杀虫剂,检出含量为1.1~500.0 ng/kg。该方法灵敏度高,准确可靠,对果蔬中有机磷杀虫剂的检测具有良好的应用潜力。     

共轭微孔聚合物的制备与应用

共轭微孔聚合物(CMPs)是一类有机多孔聚合物,与常规共轭聚合物或多孔材料相比,其最大的特点是既有π共轭骨架又具有大量微孔.这类材料在解决能源和环境问题方面显示出巨大的潜力,已在气体吸附、非均相催化、发光材料、化学传感器、电能存储和生物杂化物等领域显示出巨大的应用前景.目前已开发出多种用于CMPs结构单元设计与合成的新...     

具有多级复合孔TiO2薄膜的合成及吸附DNA的性能

本文以高分子聚合物(F127)为模板, 以强疏水的1,3,5-三甲基苯为有机添加物, 通过旋转覆膜的方法制备出具有多级复合孔的二氧化钛晶体薄膜, 并采用TEM和SEM对样品结构进行了分析, 同时考察了这种薄膜对DNA分子的吸附性能.     

共轭微孔聚合物及其复合材料的制备及应用

共轭微孔聚合物是一类具有扩展共轭体系的骨架材料,具有比表面积大、稳定性高、微孔大小和体积可精确调控等特点。由于其独特的结构特点,共轭微孔聚合物在各方面展现出巨大的应用潜力,本文综述了共轭微孔聚合物及复合材料的制备方法,以及共轭微孔聚合物在气体吸附和储存、污染物的富集、非均相催化、光发射、化学传感器、光捕集、电能存储等方面的应用。     

柱芳烃基多孔聚合物的制备及其吸附性能

将柱[5]芳烃与1,3,5-三乙炔苯(TEB)通过Sonogashira偶联反应制备了一类新型多孔有机聚合物P[5]-TEB,进而通过脱甲基反应对其进行改性得到多羟基的多孔聚合物P[5]OH-TEB,对二者的物理化学性质和吸附性能进行研究。 氮吸附测试表明,羟基的引入使P[5]OH-TEB的比表面积变大,同时引入微孔结构。 染料吸附实验表明,两聚合物对亚甲基蓝吸附过程符合Langmuir模型,P[5]OH-TEB对亚甲基蓝有更大的吸附量;吸附动力学试验表明,吸附过程更符合拟二级动力学模型,属于化学吸附过程,改性之后P[5]OH-TEB有更快的吸附速率;选择性吸附实验表明,羟基引入聚合物后聚合物对阳离子染料的吸附性能提升,对阴离子染料的吸附效果变差。     

四苯基乙烯基共轭微孔聚合物的制备及其气体吸附

共轭微孔聚合物由于其在气体吸附与分离、非均相催化和光电子等领域的巨大应用前景而广受关注. 本文以四苯基乙烯为基本构筑单元, 通过Sonogashira-Hagihara偶联反应制备了3种共轭微孔聚合物新材料, 研究了结构组成和构建模块对制备聚合物孔性能和气体吸附性能的影响. 氮气吸附测试结果表明, 由1,1,2,2-四炔四苯基乙烯自聚合制备的TPE-CMP1具有较大的比表面积, 为1096 m²·g^-1. 在1.13 bar/273 K条件下, TPE-CMP1的CO₂吸附能力为2.36 mmol·g^-1; 在1.13 bar/77.3 K条件下, TPE-CMP1对H₂的吸附能力为1.35 wt%. 另外, 制备的共轭微孔聚合物展示出较高的CO₂/N₂选择性吸附值. 由于这类多孔聚合物材料具有合成方法简单、优良的物理化学及热稳定性、高的比表面积和CO₂吸附性能, 因此将在气体吸附与分离方面具有潜在的应用前景.     

热处理对超疏水性含氟丙烯酸酯共聚物膜表面性能的影响

以微乳液聚合法和溶液聚合法制备丙烯酸全氟烷基乙基酯和甲基丙烯酸甲酯的共聚物, 以1,1,2-三氟三氯乙烷为溶剂, 采用溶剂挥发成膜法直接制备出超疏水膜, 并研究120 ℃热处理对超疏水膜表面性能的影响. 对于用乳液聚合方法制备的超疏水膜, 随着热处理时间的延长, 滚动角表现出先逐渐增大直至完全不能滚动, 然后重新回复到极小滚动角的特殊变化过程, 而静态接触角只是略微减小, 完全不同于热处理对平滑的含氟聚合物表面接触角的影响. 扫描电镜结果显示, 聚合物膜表面形貌对应出现从微/纳复合粗糙结构到微孔粗化并重新形成微/纳复合多层粗糙结构的变化.     

富羧酸基团的共轭微孔聚合物:结构单元对孔隙和气体吸附性能的影响（英文）

共轭微孔聚合物(CMPs)骨架中的孔和极性基团对聚合物的气体吸附性能起着重要作用。阐明聚合物中极性基团的效果对该领域的进一步发展是必不可少的。为了解决这个根本问题,我们使用最简单的芳香系统-苯作为建筑单体,构筑了两个新颖的富羧酸基团的CMPs(CMP-COOH@1,CMP-COOH@2),并探讨了CMPs中游离羧酸基团的量对其孔隙、吸附焓、气体吸附和选择性的深远影响。CMP-COOH@1和CMP-COOH@2显示的BET比表面积分别为835和765 m~2?g~(-1)。这两种聚合物在二氧化碳存储方面显示了高潜力。在273 K和1.05×10~5 Pa条件下,CMP-COOH@1和CMP-COOH@2的CO_2吸附值分别为2.17和2.63 mmol?g~(-1)。我们的研究结果表明,在相同的条件下增加聚合物中羧基基团的含量可以提高材料对气体的吸附容量和选择性。     

基于苯醚型含氟二胺的聚酰亚胺膜材料的合成与表征

4,4′-二羟基二苯醚和2-氯-5-硝基三氟甲苯经Williamson反应得到4,4′-双(4-硝基-2-三氟甲基苯氧基)二苯醚;在Pd/C-水合肼还原作用下得到4,4′-双(4-氨基-2-三氟甲基苯氧基)二苯醚(p-6FAPE).采用3种苯醚型含氟二胺1,4-双(3-氨基-5-三氟甲基苯氧基)苯、1,4-双(4-氨基-2-三氟甲基苯氧基)苯和p-6FAPE分别与3,3′,4,4′-二苯醚四酸二酐(ODPA)和均苯四甲酸二酐通过两步法制备出6种含氟聚酰亚胺(PI),对其溶解性、热性能和光学性能进行研究.这些PI具有较好的溶解性,且具有良好的热稳定性;ODPA基PI在可见光波长范围具有优良的透明性,450 nm处的透光率超过80%.     

超交联多孔材料的制备及其对色氨酸的吸附行为

分别以苯、联苯和1,3,5-三苯基苯为反应单体，二甲氧基甲烷（FDA）为交联剂，1,2-二氯乙烷为反应溶剂，通过Friedel-Crafts烷基化反应，合成了一系列比表面积大的多孔芳香交联聚合物（HCP-PhH-3、HCP-PhH2-3、HCP-PhH3-3）。通过氮气吸脱附分析、热失重和红外光谱对交联聚合物的结构进行表征。结果表明，聚合物的孔结构丰富，HCP-PhH-3的比表面积可达901.50 m2/g，另外该类聚合物表现出良好的热稳定性和化学稳定性。对色氨酸的吸附研究表明，三种聚合物吸附色氨酸的吸附量顺序为HCP-PhH-3> HCP-PhH2-3> HCP-PhH3-3。经过多种溶剂的浸泡后，该类聚合物对色氨酸都表现出较好的吸附效果。HCP-PhH2-3和HCP-PhH3-3吸附色氨酸的动力学和热力学拟合曲线表明，该吸附过程属于化学反应速率控制的多层吸附过程。     

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.