硫化合物中硫K—Beta谱研究

作者应用加了限制垂直发散准直器的ＰｈｉｌｉｐｓＰ１４０４型Ｘ－射线荧光分析仪测定了多种含硫化合物中ＳＫβ谱峰值。结果表明硫酸盐中ＳＫβＴβ谱峰值能量差与分析轨道理论ＤＶ－Ｘａ方法计算结果相一致。     

用亚硝基R盐螯合树脂分离富集催化极谱法测定矿石中的铱

本文研究了利用亚硝基Ｒ盐螯合形成的树脂，分离富集试液中痕量贵金属元素铱的实验条件。并利用ＪＰ－１型示波极谱仪，在１．５０ｍｏｌ／Ｌ盐酸＋５．０×１０＾－５ｍｏｌ／Ｌ硫脲＋０．２ｍｏｌ／Ｌ盐酸＋５．０×１０＾－５ｍｏｌ／Ｌ硫脲＋０．２ｍｏｌ／Ｌ碘化钾＋碲（ρ（Ｂ）＝０．４ｍｇ／Ｌ）的混合底液中，对铱进行极谱催化波测定。在示波极谱仪上峰电位约－０．５５Ｖ（银汞齐为参比电极），可测定试液中５．０×１．０     

维生素K3亚硫酸氢钠的电化学研究

维生素Ｋ３亚硫酸氢钠在０．１ｍｏｌ／ＬＮａＣｌ＋０．０４ｍｏｌ／ＬＨＣｌ，ｐＨ＝１．８０底液中，于示波极谱仪上有一良好的二阶导数波，Ｅ″Ｐ＝－０．７４±０．０１Ｖ（ＳＣＥ），峰高与浓度在５×１０－９～１×１０－６ｍｏｌ／Ｌ以及１×１０－６～１×１０－５ｍｏｌ／Ｌ分段成线性关系，检测下限为１×１０－９ｍｏｌ／Ｌ，用于针剂含量的测定，结果良好。实验证明，当ｐＨ小于３．５９时，维生素Ｋ３亚硫酸氢钠逐渐转变为维生素Ｋ３亚硫酸，出现三个极谱峰，其中用于分析测定的峰为维生素Ｋ３亚硫酸１号位羰基的还原峰，其电极过程为扩散控制的可逆的双电子过程。     

镓－茜素紫极谱络合吸附波的研究

在含有０．０５ｍｏｌ／ＬＨＡｃ－ＮａＡｃ（ｐＨ５．６）、０．１ｍｏｌ／ＬＫＣｌ和１．５×１０￣（－５）ｍｏｌ／Ｌ茜素紫的溶液中，镓（Ⅲ）－茜素紫络合物在单扫示波极谱仪上产生一灵敏的导致极谱波，峰电位在－１．１１Ｖ（ｖｓ．ＳＣＥ），峰电流与镓（Ⅲ）浓度在２．０×１０￣（－８）～２．０×１０￣（－６）ｍｏｌ／Ｌ范围内呈线性关系，检测限达１×１０￣（－８）ｍｏＬ／Ｌ机理研究表明，峰电流是由吸附在电极表面的络合物中的中心离子和配位体同时还原而产生的。方法已应用于铝合金中镓的测定，结果满意。     

吲哚乙酸与磷钼黄反应及其极谱分析的研究

在ＮＨ３－ＮＨ４Ｃｌ缓冲溶液中（ｐＨ＝９．５），吲哚乙酸与磷钼黄的还原产物在滴汞电极上于－１．１０Ｖ（ｖｓ．ＳＣＥ）处产生一灵敏的极谱波，该波波高与吲哚乙酸的浓度在１．０×１０－７－５．０×１０－６ｍｏｌ／Ｌ范围内成线性关系，检测下限为５．０×１０－８ｍｏｌ／Ｌ。如在上述还原产物中加入偶氮胭脂红Ｂ、孔雀绿、甲基紫等染料及聚乙烯醇，可使极谱波的灵敏度提高，使吲哚乙酸的浓度在５．０×１０－８－１．０×１０－６ｍｏｌ／Ｌ范围内与波高成线性关系，检测下限降低至１．０×１０－８ｍｏｌ／Ｌ。     

示波极谱法测定微量锰

研究了在氨－氯化铵介质中，Ｍｎ（Ⅱ）与邻菲罗啉形成络合物并在示波极谱仪上产生一灵敏的吸附还原波的适宜条件和影响因素，建立了测定微量锰的新方法。测定线性范围为５．０×１０＾－８￣５．０×１０＾－６ｍｏｌ·Ｌ＾－１，检出下限为２．０×１０＾－８ｍｏｌ·Ｌ＾－１，测定了水和酒样中的锰含量，结果满意。     

碳纤维汞膜微电极1.5次微分伏安法测定米托蒽醌的研究

米托蒽醌（ＭＸＴ）能吸附在碳纤维汞膜微电极表面，阴极溶出时，产生一个灵敏的１．５次微分溶出峰，其峰电流和米托葱酿的浓度在１．０×１０－５ｍｏｌ／Ｌ～１．３×１０－９ｍｏｌ／Ｌ范围内具有良好的线性关系，经３ｍｉｎ的富集，检出限可达１．０×１０－１０ｍｏｌ／Ｌ，据此建立了测定ＭＸＴ的灵敏的新方法，本文讨论了实验条件，并对血样中的ＭＸＴ进行了测定。     

示波极谱法测定内燃机车冷却液中亚硝酸根含量

采用ＪＰ３－１型示波极谱仪，滴东电极１．５次微分，在－０．６～－１．９０Ｖ范围内，通过对多种底液组分的试验，确定了在２．００×１０＾－３ｍｏｌ．Ｌ＾－１Ｍｎ＾２＋，盐酸（ｐＨ２）底液中，ＮＯ＾－２在－１．３２Ｖ（ｖｓ．ＳＣＥ）处于生极谱法，ＮＯ２浓度在４．００×１０＾－５～４．００×１０＾－３ｍｏｌ．Ｌ＾－１范围与峰高呈线性关系。方法可用于测定内燃机车冷却液中ＮＯ２含量，其选择性好，操作简便，快速     

镓—茜素紫极谱络合吸附波的研究

在含有０．０５ｍｏｌ／Ｌ ＨＡｃ－ＮａＡｃ（ｐＨ５．６）、０．１ｍｏｌ／Ｌ ＫＣＬ和１．５×１０＾－５ｍｏｌ／Ｌ茜素紫的溶液中，镓（Ⅲ）－茜素紫络合物在单扫示波极谱仪上产生一灵敏的导数极谱波，峰电位在－１．１１Ｖ（ｖｓ．ＳＣＥ），峰电流与镓（Ⅲ）浓度在２．０×１０＾－８ｍｏｌ／Ｌ。机理研究表明，峰电流是由吸附在电极表面的络合物中的中心离子和配位体同时还原而产生的。方法已应用于铝合金中镓的测定，结果     

哌仑西平的单扫描示波极谱法测定

本报道一种测定哌仑西平的单扫描示波极谱法，在０．１ｍｏｌ／ＬＮＨ４Ｃｌ－ＮＨ３．Ｈ２Ｏ（ｐＨ８．０±０．１）缓冲液中，哌仑西平有一极谱还原波，其峰电位为－１．５１Ｖ（ｖｓ．ＳＣＥ），其一阶导数峰高与哌仑西闰浓度在６．６×１０＾－７－４．６×１０＾－６ｍｏｌ／Ｌ（ｒ＝０．９９８１）和６．６×１０＾－６－１．６×１０＾－５ｍｏｌ／Ｌ（ｒ＝０．９９９１）范围内有线性关系，检测限为３．４×１０－７ｍｏｌ     

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.     

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.     

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.     

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.     

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.     

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.