Ti（Ⅳ）－F~－－邻硝基苯基荧光酮－氯化十六烷基吡啶四元体系显色反应的研究

本文较详细研究了在Ｈ＿２ＳＯ＿４介质中，Ｔｉ（Ⅳ）－Ｆ￣－－ｏ－ＮＰＦ－ＣＰＣ体系水相光度法测定痕量钛的新方法。四元体系的最大吸收峰在５６５ｎｍ处，表观摩尔吸光系数为２．１×１０￣５Ｌ·ｍｏｌ￣（－１）·ｃｍ￣（－１），Ｓａｎｄｅｌｌ灵敏度为２．２８×１０￣（－４）μｇＴｉ／ｃｍ￣２。钛含量在０～４μｇ／２５ｍＬ范围内遵守比尔定律。方法用于土壤、粮食、牧草、蔬菜和中草药中钛的测定，结果满意。     

二安替比林基－（3－羟基）苯基甲烷光度法测定痕量钒

合成和鉴定了二安替比林基－（３－羟基）苯基甲烷（ＤＡｍＨＭ），研究了它与Ｖ（ｖ）的显色反应。在磷酸介质中，在Ｍｎ（Ⅱ）和吐温－４０存在下，ＤＡｍＨＭ与Ｖ（Ｖ）生成橙黄色化合物，λ＿（ｍａｘ）＝４８０ｎｍ，ε＝１．０３×１０￣６Ｌ·ｍｏｌ￣（－１）·ｃｍ￣（－１），Ｖ（ｖ）量在０．２～１．２ｕｇ／２５ｍＬ间符合比尔定律，体系灵敏度高，稳定性好，用于中草药中痕量钒的测定，结果满意。     

Fe（Ⅲ）－TEA－5－Br－PADAP－H_2O_2体系中催化波的研究及其应

在０．２ｍｏｌ·Ｌ￣（－１）ＮＨ＿４Ｃｌ－ＮＨ＿３·Ｈ＿２Ｏ底液中，（ｐＨ为９．２６），得到一个极为灵敏的Ｆｅ（Ⅲ）－ＴＥＡ－５－Ｂｒ－ＰＡＤＡＰ－Ｈ＿２Ｏ＿２配合吸附催化波，其峰电位为－０．７１Ｖ（ｖｓ．ＳＣＥ）。铁浓度在１．８×１０￣（－１０）～５．４×１０￣（－６）ｍｏｌ·Ｌ￣（－１）范围内与二阶导数波高呈线性关系。对该极谱波的性质进行了研究，证明是一种配合吸附催化波，并成功地应用于各类水样，钒催化剂中微量或痕量铁的测定。     

无机还原剂与光泽精化学发光反应的研究Ⅲ．钒（Ⅱ）－光泽精体系的化学发光反应

本文采用装有Ｊｏｎｅｓ柱的流动注射系统，研究了钒（Ⅱ）－光泽精体系的化学发光反应。在此基础上建立了痕量钒测定的新方法。方法的检出限３×１０￣（－１０）ｇ·ｍＬ￣（－１）；对于１．０×１０￣（－７）ｇ·ｍＬ￣（－１）钒标准溶液测定的相对标准偏差为２％（ｎ＝１１）；线性范围１．０×１０￣（－９）～９．０×１０￣（－５）ｇ·ｍＬ￣（－１），相关系数大于０．９９８０。该方法已用于水样中痕量钒的测定。对于反应机理，本文也进行了探讨。     

镍（Ⅱ）与2－（5－溴－2－吡啶偶氮）－5－二甲氨基苯胺显色反应的研究及铝合金中镍的测定

本文研究了新显色剂２－（５－溴－２－吡啶偶氮）－５－二甲氨基苯胺与镍（Ⅱ）的反应条件。试验结果发现，在阴离子表面活性剂十二烷基硫酸钠存在下，在ｐＨ５．２～６．５范围内，试剂与镍（Ⅱ）形成稳定的２∶１配合物。其最大吸收波长在５７０ｎｍ处，表观摩尔吸光系数为１．２４×１０￣５Ｌ·ｍｏｌ￣（－１）·ｃｍ￣（－１）。镍（Ⅱ）浓度在０～０．４μｇ·ｍＬ￣（－１）之间符合比尔定律。以硫脲和氟化按作掩蔽剂，可消除Ｃｕ￣（２＋）、Ｐｄ￣（２＋）、Ｆｅ￣（３＋）等离子的干扰。所拟方法用于铝合金中微量镍的测定，结果满意。     

2－（4－苯基－2－噻唑偶氮）－5－［（N，N－二羧基甲基）氨基］苯甲酸的合成及其与钯应用的研究

本文报道了新试剂２－（４－苯基－２－噻唑偶氮）－５－［（Ｎ，Ｎ－二羧基甲基）氨基］苯甲酸的合成及其与金属离子的显色反应。详细讨论该试剂与钯显色反应的最适条件，在酸性条件下，试剂与钯形成２：１蓝色络合物，其稳定常数Ｋ＿稳＝５．３９×１Ｏ￣（１１），采用双波长法测定，络合物的摩尔吸光系数ε＿（６７６．４－４８６．０）＝５．６１×１０￣４Ｌ·ｍｏｌ￣（－１）·ｃｍ￣（－１），比单波长测定的灵敏度（ε＿（６７６．４＝３．５８×１０￣４）提高了５７％。试剂的灵敏度高，选择性好，可直接用于铂－钯催化剂中微量他的测定，结果满意。     

新荧光试剂3－对甲苯基－5－（2’－羧基苯偶氮）绕丹宁的合成及荧光光度法测定蚕丝制品中痕量铜的研究

本文报道了新荧光试剂３－对甲苯基－５－（２’－羧基苯偶氨）绕丹宁（ＰＭ－ＰＲＡＣＰ）的合成。用元素分析、红外光谱、核磁共振氢谱和质谱确证了其结构，研究了其荧光性质。在ｐＨ５．６时，该试剂与Ｃｕ￣（２＋）形成稳定的荧光螯合物，且在λ＿（ｅｘ）／λ＿（ｅｍ）＝３０５ｎｍ／４０５ｎｍ产生强烈荧光。其荧光强度与Ｃｕ￣（２＋）的浓度在０～１．６μｇ／２５ｍＬ范围内呈线性关系，检测限为５×１０￣（－４）μｇ／ｇ。已用于痕量铜（Ⅱ）的荧光分光光度法测定。测定了蚕茧、蚕丝和丝绸中的痕量铜，结果满意。     

卟啉试剂光度法间接测定硫离子的研究（1）

本文以ＴＰＰＳ４、Ｔ（４－ＭＯＰ）ＰＳ４和Ｔ（４－ＭＰ）ＰＳ４为例，研究了Ａｇ·ｐｈｅｎ·ＰＰ光度法间接测定废水中痕量硫离子的有关条件。同时用上述三种卟啉试剂试验了Ｃｕ￣（２＋）、Ｈｇ￣（２＋）、Ｃｄ￣（２＋）、Ｐｂ￣（２＋）等软酸和交界酸间接测定Ｓ￣（２－）的可能性，结果表明，Ｈｇ－ＰＰ也可用于间接测定Ｓ（２－）。最后，对Ｈ＿２Ｓ的吸收液进行了筛选。     

2－（2－噻唑偶氮）－5－〔N，N－二羧基甲基）氨基〕苯甲酸与钯显色反应的研究及其应用

报道了一种对钯离子具有高灵敏度和选择性的新试剂２－（２－噻唑偶氮）－５－［（Ｎ，Ｎ－二羧基甲基）氨基］苯甲酸（ＴＡＤＣＡＢ）。在０．５ｍｏｌ／ＬＨＮＯ＿３介质中，ＴＡＤＣＡＢ与Ｐｄ（Ⅱ）形成蓝色配合物，组成为Ｐｄ：ＴＡＤＣＡＢ＝１：２，最大吸收波长６５２ｎｍ。钯浓度在０～１．４μｇ／ｍＬ范围内符合比耳定律。用双波长法测定，表观摩尔吸光系数ε＿（６５２．０～５３３．６）＝８．２×１０￣４Ｌ·ｍｏｌ￣（－１）·ｃｍ￣（－１），可以允许大量金属离子共存。所确立的方法无需掩蔽剂和其它分离手段，即可直接用于Ｐｔ－Ｐｄ催化剂中微量钯的测定，结果满意。     

还原剂与鲁米诺化学发光反应的研究（Ⅳ）──痕量铀的流动注射－化学发光测定

本文利用流动注射系统研究了由Ｊｏｎｅｓ柱产生的铀（Ⅲ）与鲁米诺之间的化学发光反应，建立了痕量铀的化学发光测定法。方法的检出限是３×１０￣（－１０）ｇ／ｍＬ铀。校准曲线的线性范围是１×１０￣（－９）～４×１０￣（－６）ｇ／ｍＬ铀，相对标准偏差为２％（测定２×１０￣（－９）ｇ／ｍＬ铀，ｎ＝１１）。对于反应机理进行了初步研究。     

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%.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

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.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.     

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.