镉—溴化物—罗丹明B高灵敏显色反应的研究：离心光度法测定镉

本研究了一个高灵敏的测定镉的方法，离心光度法，该体系络合物λｍａｘ＝５６０ｎｍ，表观摩尔吸系数ε５６０＝５．０６×１０＾８Ｌ．ｍｏｌ＾－１．ｃｍ＾－１，Ｃｄ＾２＋浓度０．１０×１０＾－２－１．０×１０＾－２μｇ／１０ｍＬ呈线性关系，本法已用于血清和水中痕量镉的测定，探讨了高灵敏的显色反应机理。     

新试剂苯并噻唑重氮氨基偶氮苯与镉的显色反应研究及其应用

在Ｔｒｉｔｏｎ Ｘ－１００存在下，ｐＨ９．０－１０．０时，新试剂苯并噻唑重氮氨基偶氮苯与镉形成３：１的橙红色络合物，最大吸收波长位于５３０ｎｍ，表观摩尔吸光系数为１．９１×１０＾－５Ｌ．ｍｏｌ＾－１；ｃｍ＾－１，镉量在０－１２μｇ／２５ｍＬ范围内遵守比尔定律。在混合掩蔽剂存在下，显色反应具有良好的选择性，直接应用于工业废水中微量镉的测定，获得了满意的结果。     

安替比林基重氮基—2,4—二硝基苯及其与镉的显色反应

合成了安替比林基重氮氨基－２，４－二硝基苯（ＡＰＤＮＢＴ）新试剂，并首先研究了它的分析性质及其与镉的显色反应。在ＴｒｉｔｏｎＸ－１００存在下，试剂的两级质子离解常数的ｐＫａ值分别是０．８和１０．８；在ｐＨ＝１０．２～１２．０的Ｂ－Ｒ缓冲溶液中，试剂与镉生成１：２的黄色配合物，呈褪色反应，吸光度差值最大的波长为５４０ｎｍ，其表观摩尔吸光系数为１．５２×１０＾５Ｌ／（ｍｏｌ．ｃｍ），线性范围每２５ｍＬ     

2—[2‘—苯并噻唑偶氮]—1,8—二羟基萘—3,6—二磺酸的合成及与铝的显…

本合成了新的显色试剂２－［２＇－苯并噻唑偶氮］－１，８－二羟基萘－３，６－二磺酸，并研究了与铝的显色反应，在ＣＴＭＡＢ存在下，铝与试剂于ＰＨ７．０－８．０的缓冲溶液中的形成稳定的深紫红色络合物，组成为Ａｌ（Ⅲ）：Ｒ＝１：２，表观摩尔吸光系数为１．４６×１０＾５Ｌ．ｍｏｌ＾－１．ｃｍ＾－１，铝浓度在０－５．０μｇ／２５ｍＬ范围内符合比尔定律。     

显色试剂6—硝基—苯并噻唑重氮氨基偶氮苯的合成及与镉的显色反应

合成了新的显色试剂６－硝基－苯并噻唑重氮氨基偶氮苯，并研究了在乳化剂ＯＰ存在下马镉的显色反应。镉与试剂于ｐＨ ９．０～１０．０的缓冲介质中形成稳定的红色络合物，表观摩尔吸光系数 ε５２６＝２． ４５ × １０５Ｌ·ｍｏｌ－１·ｃｍ－１，镉浓度在０～ ０． ５ ｍｇ／Ｌ范围内符合比尔定律。该方法灵敏度高，选择性好，并用于废水和环境水样中的微量镉的测定。     

镉—双硫腙—CTMAB显色体系的研究及应用

研究了阳离子表面活性剂ＣＴＭＡＢ存在下，镉与双硫腙显色反应的条件及配合物的组成，在０．１６ｍｏｌ／Ｌ的ＮａＯＨ介质中，镉与双硫腙形成一红色配合物，该配合物的λｍａｘ＝５４０ｎｍ，ε５４０＝８．８９×１０＾４Ｌ．ｍｏｌ＾－１．ｃｍ＾－１镉与双硫腙的配合比为１：３，镉量在０～２５μｇ／２５ｍＬ范围内符合比尔定律，方法用于水样中镉的测定，获得满意结果。     

新显色剂—6硝基—苯并噻唑重氮氨基偶氮苯与汞的显色反应及其应用研究

研究了新显色试剂６－硝基－苯并噻唑重氮氨基偶氮苯与Ｈｇ（Ⅱ）的显色反应。在乳化剂ＯＰ存在下，于ｐＨ１０．０的缓冲溶液中，Ｈｇ（Ⅱ）与显色剂形成１：２的稳定红色络合物。络合物的λｍａｘ＝５１５ｎｍ，其表观摩尔吸光系数为１．５３×１０＾５Ｌ·ｍｏｌ＾－１·ｃｍ＾－１，Ｈｇ（Ⅱ）含量在０￣５μｇ／１０ｍＬ范围符合比尔定律，样品分析结果令人满意。     

安替比林基重氮氨基—2,4—二硝基苯与银（I）的显色反应及其应用

本文报道了安替比林基重氮氨基－２，４－二硝基苯（ＡＰＤＮＢＴ）与银（Ｉ）的显色反应，在吐温－８０存在下，ＰＨ＝９．０－１０．０的范围内，试剂与银（Ｉ）形成２：１的配合物；配合物对试剂的最大吸收在４８５ｎｍ处，ε为７．２×１０＾４Ｌ＾－１．ｍｏｌ．ｃｍ＾－１提出了消除阳离子干燥的银镜分离法；方法用于洞察工样及照相显影液中银的含是一定回收率为９６－１０３％，相对标准偏差小于２．０％。     

2—[2‘—（6—溴—苯并噻唑）—偶氮]—1,8—二羟基萘—3,6—二磺酸的合成及…

本合成了一种新的苯并噻唑类显色试剂－－２－〔２′－（６－溴－苯并噻唑）－偶氮〕－１，８－二羟基萘－３，６－二磺酸（简称Ｂｒ－ＢＴＣＡ），并研究了其与钛的显色反应。在ＣＴＭＡＢ存在下，钛与试剂形成稳定的络合物，其ε６１６＝１．１５×１０＾５Ｌ．ｍｏｌ＾－１．ｃｍ＾－１，组成为Ｔｉ（Ⅳ）：Ｒ：＝１：１，钛浓度在０－０．５ｍｇ／Ｌ范围内符合比尔定律，该方法灵敏度高，选择性好，并用于铝合金及硅铁试样中微     

新显色剂二胺替比林基—4—羟基苯基甲烷与铈（Ⅳ）的显色反应

合成了二安替比林基－４－羟基苯基甲烷。研究了它与铈的显色反应，在稀磷酸介质和Ｔｗｅｅｎ－６０存在下，试剂与铈生成橙红色化合物，λｍａｘ＝４５０ｎｍ，ε＝６．８＊ｄ１０＾ｄ５Ｌ．ｍｏｌ＾－１．ｃｍ，Ｃｅ（Ⅳ）量在０．１－０．８μｇ／２５ｍＬ间符合比尔定律。用于镁合金和锌矿石中微量铈的测定，结果满意。     

A carbanion induced synthesis of highly congested pyrazole and imidazole containing heterocycles

An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions.     

Selective synthesis of 4,5-dihydroimidazo- and imidazo[1,5-a]quinoxalines via modified Pictet–Spengler reaction

An efficient tandem approach for the selective synthesis of 4,5-dihydroimidazo[1,5-a]quinoxalines 6a–g and imidazo[1,5-a]quinoxalines 7a–h by the reaction of 2-imidazolyl anilines 4a–c with aryl aldehydes 5a–k under mild reaction conditions is described. Introduction of electron releasing alkyl groups in substrates 4a–b was found to be instrumental for the success of the reaction.     

Understanding the Diels-Alder reactivity of 1,2-azaborine analogues

The Diels-Alder reactivity of 1,2-heteroborines (H₄C₄B(H)X, X?=?NH, PH, AsH; O, S, Se) has been computationally explored by means of Density Functional Theory (DFT) calculations. The influence of the HB?=?X fragment on the reactivity of the system has been quantitatively analyzed in detail by means of the so-called Activation Strain Model (ASM) of reactivity. It is found that the interaction between these species and the dienophile is significantly stronger than that computed for their all-carbon isoelectronic counterpart, benzene. In addition, the strain energy plays a key role in the observed reactivity trends. The role of the aromaticity strength of these heteroarenes on the reactivity is also assessed.     

Synthesis of N-substituted carbazolones from α-iodo enaminones via Pd(0)-catalyzed intramolecular coupling under microwave irradiation

A variety of N-aryl and N-alkyl carbazolones were conveniently achieved in good to high yields via Pd₂(dba)₃-mediated intramolecular coupling of N-substituted α-iodo enaminones under microwave irradiation. The Pd(0)-catalyzed cyclization was found to proceed favorably with the more electron-deficient phenyl ring during the reactions involving unsymmetrical N,N-diaryl α-iodo enaminones. This unique property enables the construction of carbazolone skeleton containing nitro substituted benzenoid ring.     

Synthesis of substituted 2,4,5,6-tetrahydrocyclopenta[c]pyrazoles and 2,4,5,6-tetrahydropyrrolo[3,4-c]pyrazoles by intramolecular nitrilimine cycloaddition

Both substituted 2,4,5,6-tetrahydrocyclopenta[c]pyrazoles and 2,4,5,6-tetrahydropyrrolo[3,4-c]pyrazoles have been synthesized by the 3+2 intramolecular dipolar cycloaddition of nitrilimines to alkynes. This cyclization has been extended to more versatile 3-bromo derivatives by the use of alkynylbromides as dipolarophiles.     

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%.     

Catalyst free,visible-light promoted photoaddition reactions between C60 and N-trimethylsilylmethyl-substituted tertiary amines for synthesis of aminomethyl-1,2-dihydrofullerenes

An efficient and benign method for the preparation of aminomethyl-substituted fullerenes has been developed. The process, involving catalyst free, visible-light irradiation of 10% EtOH-toluene solutions containing fullerene C₆₀ and N-trimethylsilylmethyl-substituted amines by using a 20 W compact fluorescent lamp, leads to formation of aminomethyl-substituted fullerene adducts in a highly efficient manner. The photoaddition reaction takes place via a pathway initiated by visible light absorption by C₆₀, followed by SET from the amine to the triplet excited state of C₆₀. Ethanol-promoted desilylation of the resulting a minimum radical then generates the corresponding α-amino radical which couples with the C₆₀ radical anion to form the anion precursor of the fullerene adducts. The new approach using visible-light takes place under mild conditions and it does not require the use of photocatalysts. Thus, the method developed in this effort could broadens the range of functionalized fullerene derivatives that can be readily prepared.     

Highly efficient and stereoselective cycloaddition of nitrones to indolyl- and pyrrolylacrylates

The reactions of various nitrones with indolyl- and pyrrolylacrylates proceeds regioselectively with high diastereoselectivity in the case of aldonitrones, and represents an effective method for obtaining new indolyl- and pyrrolyl-substituted isoxazolidine carboxylates stabilized by weak (CH?O) and moderate (NH?N) strength intramolecular hydrogen bonding. The resulting cycloadducts exhibit promising in vitro anti-influenza activities.     

Transition metal-free direct amination of benzoxazoles using formamides as nitrogen sources

A transition metal-free method for the direct amination of benzoxazoles using formamides as nitrogen sources is reported, which was mediated by an inexpensive and environmentally friendly tetrabutylammonium iodide/tert-butyl hydroperoxide system and gave the 2-aminobenzoxazole derivatives with moderate to good yields.     

l-Proline-catalyzed five-component domino reaction leading to multifunctionalized 1,2,3,4-tetrahydropyridines

Multifunctionalized 1,2,3,4-tetrahydropyridines are concisely synthesized in good yields via l-proline-catalyzed or l-proline/FeCl₃-cocatalyzed one-pot multicomponent reactions (MCRs). The MCRs involve a domino hydroamination/prins reaction/Mannich-type reaction/intramolecular dehydration-cyclization process. The molecular structure of 5baa, one of multifunctionalized 1,2,3,4-tetrahydropyridines, was confirmed by single-crystal X-ray diffraction.