过氧草酸酯结构和取代基对其化学发光的影响(英)

通过单晶测定和理论研究阐述了过氧草酸酯化学发光中取代基的影响 .几种典型的芳基草酸酯所 观察的化学发光效率随着羰基碳原子的正电荷增加而递增 .通过电子密度函数的计算印证了芳基草酸酯 对过氧化氢亲核进攻的活泼性 .     

过氧草酸酯类化学发光激发荧光

过氧草酸酯类化学发光激发荧光是迄今发现的效率最高的一种化学发光激发荧光。本文对其机理进行了讨论，介绍了其主要用途，并讨论了不同的化学发光能量接受体（荧光剂分子）、芳基草酸酯、添加剂对化学发光强度和寿命的影响。     

草酸二芳基酯-过氧化氢化学发光体系的原理与应用

草酸二芳基酯-过氧化氢化学发光体系是一种原理简单、效果明显、趣味性强的化学发光体系。通过体系中的染料将反应的化学能转变为光能,广泛应用于发光玩具、紧急照明、搜寻救援等领域。根据所使用染料的不同,化学发光可以发出不同颜色的可见光以及肉眼不可见的红外光。本科普实验通过多种化学发光染料,介绍了化学发光的原理和红、绿、蓝、红外发光的波长范围,以及展示了利用红光、绿光、蓝光实现多种颜色发光的原理。本文设计了不同染料的混合发光、火山喷发模拟、自制化学发光荧光笔、粉笔彩色发光、自制荧光棒等多组化学发光科普实验和互动环节,寓教于乐,生动有趣。     

影响双(2-丁氧羰基-3,4,6-三氯苯基)草酸酯化学发光体系的因素

过氧草酸酯类化学发光是一类以多氯代水杨酸酯与草酰氯反应生成的草酸酯、过氧化氢和荧光剂为主要组成的化学发光体［１，２］．它除了具有发光效率高，强度大，寿命长的特点外，还可以通过选择荧光剂调节发光的颜色．采用这类发光体系可制成多种化学光源．在草酸酯和荧光...     

化学发光试剂的结构修饰及化学发光性能研究进展

化学发光法灵敏度高、背景干扰小,尤其适合于复杂体系中微量被测物的分析.吖啶鎓、鲁米诺、过氧草酸酯、1,2.二氧杂环丁烷等是应用广泛、量子产率较高的化学发光试剂.介绍了它们及其衍生物的结构修饰与化学发光性能研究进展,并展望了化学发光试剂修饰的前景.     

微流控芯片化学发光检测系统的设计及其应用

通过标准光刻、化学刻蚀及热键合技术制作微流控电泳芯片,在芯片上集成流通式化学发光检测池,实现样品的芯片电泳分离化学发光检测.采用双(2,4,6-三氣苯基)草酸酯(TCPO)-过氧化氢化学发光体系,通过微泵输送化学发光试剂.单酰化苯并氨基酸和单酰化肌氨酸在该系统中得以成功地分离检测,其检测限分别达到2.8和3.2 μmol/L.     

化学发光技术在色谱柱后检测中的应用

化学发光与色谱联用具有选择性好、灵敏度高等优点,应用广泛.本文主要介绍近三年来化学发光包括鲁米诺、过氧草酸酯、Ru(bipy)33 、无机等体系作为液相色谱柱后检测及含氮、含硫化合物气相化学发光等体系作为气相色谱柱后检测的现状.     

通过芳磺酸酯不同化学键的可选择性断裂构建不同的芳基醚

实现了利用芳磺酸酯作原料通过各种化学键的选择性断裂制备芳基烷基醚和二芳基醚,实现了利用吸电子基取代的芳磺酰氯与酚的反应来制备二芳基醚.在K2CO3作用下,分别利用酯基部分苯环上是吸电子基取代的芳磺酸芳基酯通过S—O键断裂与醇的反应,芳磺酸烷基酯通过C—O键断裂与酚的反应来合成芳基烷基醚.在K3PO4作用下,利用吸电子基...     

镍催化酚衍生物的Suzuki-Miyaura偶联反应研究进展

过渡金属镍催化的Suzuki-Miyaura偶联反应在有机合成中有着广泛的应用.综述了近年来以过渡金属镍催化的以酚的衍生物为底物的偶联反应的研究进展.主要包括芳基磺酸酯、氨基磺酸芳基酯、碳酸芳基酯、芳基羧酸酯、氨基甲酸芳基酯、芳基磷酸酯、芳醚、杂芳醚和酚盐的偶联反应.     

化学发光免疫分析技术及其在农药残留检测中的应用进展

化学发光免疫分析技术发展迅速,具有特异性强、灵敏度高、线性范围宽、操作简单、成本底、检测时间短、易于实现自动化等优点,在农残检测领域得到广泛应用。以化学发光免疫分析为基础,介绍了吖啶酯类、鲁米诺类、咪唑类、苯酚类及芳基草酸酯类5种化学发光剂,及化学发光免疫分析法、荧光化学发光免疫分析法、化学发光酶联免疫分析法和电化学发光免疫分析法4种常见的分析方法,重点综述了化学发光免疫分析技术在农药残留检测中的应用,并对该领域的研究前景进行了展望,旨在为农药残留检测相关研究提供参考。     

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.